Metal modified y zeolite, its preparation and use

ABSTRACT

The present invention relates to a metal modified Y zeolite, its preparation and use. Said zeolite contains 1-15 wt % of IVB group metal as oxide and is characterized in that the ratio of the zeolite surface&#39;s IVB group metal content to the zeolite interior&#39;s IVB group metal content is not higher than 0.2; and/or the ratio of the distorted tetrahedral-coordinated framework aluminum to the tetrahedral-coordinated framework aluminum in the zeolite lattice structure is (0.1-0.8):1.

INCORPORATION BY REFERENCE

The present application claims priority of Chinese Patent ApplicationNo. CN201310499703.9 and CN201310499736.3, both filed on Oct. 22, 2013,and incorporates by reference the entirety of these two applications.

TECHNICAL FIELD

The present invention relates to a metal modified Y zeolite, itspreparation and use.

BACKGROUND

Along the catalytic cracking feedstock becomes heavier and heavier, itis essential for the catalytic cracking catalyst to have both higheractivity and higher thermal and hydrothermal stabilities to increase theabilities of heavy conversion and anti-heavy metal contamination.Therefore, it is required that the main active component in thecatalytic cracking catalyst, i.e. Y zeolite, has high thermal andhydrothermal stabilities, and remains a suitable contribution of acidicactive centers.

The rare earth (RE) modified Y zeolite has relative high thermal andhydrothermal stabilities, and is widely used in the FCC catalyst.However, the sharp rise in the rare earth price results in theremarkable increase in the cost of the FCC catalyst. Therefore, it isdesirable to introduce other metal ions to the Y zeolite, to reduce therare earth content in the Y zeolite and to ensure a hydrothermalstability comparable to the Y zeolite with high rare earth content.

CN1350887A, CN1765492A, and US2007010698A1 propose the preparationmethods for metal-modified Y zeolites. However, with comparison to therare earth modified Y zeolite, the above metal-modified Y zeolites arepoor in the thermal and hydrothermal stabilities.

CN101898144A and CN101134576A propose the modification to the frameworkof Y zeolites to increase the thermal and hydrothermal stabilities of Yzeolites. However, the obtained non-rare earth metal-modified Y zeolitesproduce a low gasoline yield in the catalytic cracking.

SUMMARY

Aiming to the problems in the prior art, the present invention proposesa metal modified Y zeolite and its preparation method. Themetal-modified Y zeolite is modified with non-rare earth metal elements,and has thermal and hydrothermal stability comparable to the rare earthmodified Y zeolite. And upon being used in the catalytic crackingcatalyst, the catalyst can show excellent properties in crackingactivities, gasoline yield, and coke selectivity.

In one aspect, the present invention provides a metal modified Yzeolite, characterized in that: the ratio of the zeolite surface's IVBgroup metal content to the zeolite interior's IVB group metal content isnot higher than 0.2; and/or the ratio of the distortedtetrahedral-coordinated framework aluminum to thetetrahedral-coordinated framework aluminum in the zeolite latticestructure is (0.1-0.8):1.

In another aspect, the present invention provides a process forpreparing the metal-modified Y zeolite, comprising:

(1) a Y-zeolite raw material is subjected to dewatering so that the rawmaterial has a water content by weight of not higher than 5%;

(2) the Y zeolite obtained from step (1) is contacted with a mixture ofa compound containing IVB group metal and an organic solvent, and theresulting mixture is optionally filtered and/or dried;

(3) the Y zeolite obtained from step (2) is calcined at 300-700° C.,preferably for at least 0.5 hour, e.g. 0.5-5 hours;

(4) the Y zeolite obtained from step (3) is contacted with an aqueousacid solution, and then calcined at 400-800° C. under 1-100% steamcondition for 0.5-5 hours to produce the metal-modified Y zeolitecontaining the IVB group metal; the acid concentration, as H+, is0.1-2.0 mol/L.

In another aspect, the present invention provides a process forpreparing the metal-modified Y zeolite, comprising:

(1) a Y zeolite is treated by contacting with an acid solution and/or anaqueous EDTA solution; wherein said acid is an organic acid and/or aninorganic acid;

(2) the product obtained from the step (1) is dewatered at a temperaturebelow 400° C., so that the water content in the zeolite is not higherthan 5 wt %;

(3) the zeolite obtained from the step (2) is impregnated with a metalin an organic solvent;

(4) the metal impregnated Y zeolite obtained from the step (3) and anorganic solvent are added to a vessel at a solid-to-liquid weight ratioof 1:(5-50) and mixed, an inert gas such as one or more of nitrogen andhelium is introduced to the vessel, and the vessel is kept under apressure of 0-2.0 MPa (gauge pressure) at a temperature in the rangefrom room temperature to 200° C. for at least one hour, e.g. 1-48 hours;filtering and/or drying are optionally conducted, preferably filteringand drying are conducted;

(5) the zeolite obtained from the step (4) is calcined; the calcinationis conducted in an inert gas atmosphere, the calcination temperature is300-700° C., the calcination time is at least 0.5 hour, e.g. 0.5-5hours.

In another aspect, the present invention also provides a catalyticcracking catalyst containing the metal-modified Y zeolite and thepreparation method thereof.

Specifically, the present invention involves the following technicalsolutions:

1. A metal modified Y zeolite, which contains 1-15 wt % of IVB groupmetal as oxide, wherein the metal-modified Y zeolite has a ratio of thedistorted tetrahedral-coordinated framework aluminum to thetetrahedral-coordinated framework aluminum in the lattice structure of0.1-0.8, e.g. 0.2-0.8.

2. The metal modified Y zeolite of any one of the previous solutions,which has a specific surface area of 600-850 m²/g or 600-750 m²/g, aunit cell size a0 of 2.448-2.458 nm or 2.450-2.455 nm, a crystallinityof not less than 60%, and optionally a SiO₂/Al₂O₃ molar ratio (frameworkSi/Al atom ratio) of 5-50, and the percent of the secondary pores (porediameter of 6-20 nm) to the total secondary pores (pore diameter of2-100 nm) being 30-50% or 50%-65%.

3. The metal modified Y zeolite of any one of the previous solutions,wherein the modifying metal is Ti and/or Zr, wherein relative to thenon-modified Y zeolite, the antisymmetric stretching vibration frequency(1050-1150 cm⁻¹) and the symmetric stretching vibration frequency(750-820 cm⁻¹) in the infrared spectrum of the metal-modified Y zeolitedo not red-shift in a direction toward the lower frequency.

4. The metal-modified Y zeolite of any one of the previous solutions,which has an anhydrous chemical composition formula, as oxide and byweight, of (0-2)Na₂O.(1-15)MO₂.(10-25)Al₂O₃.(65-75)SiO₂ or(0.1-1.2)Na₂O.(1-10)MO₂.(20-24)Al₂O₃.(67-74)SiO₂, wherein M is a IVBgroup metal, selected from one or more of Ti, Zr, Hf and Rf.

5. The metal modified Y zeolite of any one of the previous solutions,wherein the IVB group metal is Ti and/or Zr, and the metal-modified Yzeolite is free of both framework Ti and framework Zr.

6. The metal modified Y zeolite of any one of the previous solutions,wherein the ratio of the zeolite surface's IVB group metal content tothe zeolite interior's IVB group metal content is not higher than 0.2.

7. The metal modified Y zeolite of any one of the previous solutions,wherein the content of the IVB group metal as oxide is 1-10 wt %.

8. The metal modified Y zeolite of any one of the previous solutions,wherein the IVB group metal comprises Ti and/or Zr.

9. A process for preparing a metal modified Y zeolite, comprising thesteps of:

(1) a Y zeolite is contacted with an acid solution and/or an aqueousEDTA solution; wherein said acid is an organic acid and/or an inorganicacid;

(2) the product obtained from the step (1) is dewatered at a temperaturebelow 400° C., so that the water content in the zeolite is not higherthan 5 wt %;

(3) the zeolite obtained from the step (2) is impregnated with a metalin an organic solvent;

(4) the metal impregnated Y zeolite obtained from the step (3) and anorganic solvent are added to a vessel at a solid-to-liquid weight ratioof 1:5-50, an inert gas is introduced to the vessel, and the vessel iskept under a pressure of 0-2.0 MPa, preferably 0.1-2 MPa (gaugepressure) at a temperature in the range from room temperature to 200° C.for at least one hour; filtering and/or drying is optionally conducted;

(5) the zeolite obtained from the step (4) is calcined; the calcinationis conducted in an inert gas atmosphere, the calcination temperature is300-700° C., the calcination time is 0.5-5 hours.

10. The process of any one of the previous solutions, wherein in thestep (1), the Y zeolite is one or more of NaY, NaHY, NaNH₄Y, NH₄Y, HY,USY, DASY zeolite, once-exchanged-once-calcined Y zeolite,twice-exchanged-twice-calcined Y zeolite, andtwice-exchanged-once-calcined Y zeolite.

11. The process of any one of the previous solutions, wherein in thestep (1), the Y zeolite is contacted with the acid solution in asolid-to-liquid weight ratio of 1:5-1:20 at a temperature in a rangefrom room temperature to 100° C. for at least 0.5 hour, then filteredand washed; the acid solution has an acid concentration, as H⁺, of 0.1-1mol/L.

12. The process of any one of the previous solutions, wherein thecontact time is 0.5-3 hours; the acid is an inorganic acid and/or anorganic acid; wherein the inorganic acid is one or more of hydrochloricacid, sulfuric acid and nitric acid; and the organic acid is one or moreof formic acid, acetic acid, oxalic acid, citric acid.

13. The process of any one of the previous solutions, wherein in thestep (2), the dewatering is to calcine the zeolite obtained from thestep (1) at 200-400° C. for 2-10 hours.

14. The process of any one of the previous solutions, wherein in thestep (3), the impregnation with the metal in the organic solventcomprises the organic solvent in which a compound containing IVB groupmetal is solved is mixed with the zeolite obtained from the step (2),and the resulting mixture is kept for at least 0.5 hour, wherein thesolid-to-liquid weight ratio of the Y zeolite and the organic solvent is1:(0.5-5).

15. The process of any one of the previous solutions, wherein in thestep (3), the resulting mixture is kept by standing or being stirred for0.5-12 hours.

16. The process of any one of the previous solutions, wherein in thestep (3), the solid-to-liquid weight ratio of the Y zeolite and theorganic solvent is 1:1-2.

17. The process of any one of the previous solutions, wherein thecompound containing IVB group metal is a Ti-containing compound and/or aZr-containing compound; the Ti-containing compound is one or more oftitanium sulfate, titanyl sulfate, titanium tetrachloride, titaniumtrichloride, tetrabutyl titanate, and ammonium fluotitanate, and theZr-containing compound is one or more of zirconium tetrachloride,zirconium sulphate, zirconium nitrate, zirconium oxychloride, zirconiumacetate, and zirconium isopropoxide.

18. The process of any one of the previous solutions, wherein in thestep (4), the vessel is kept for 1-48 hours.

19. The process of any one of the previous solutions, wherein in thestep (4), the pressure is 0.5-1.5 MPa, the temperature is from roomtemperature to 150° C., the time is 4-24 hours, and the solid-to-liquidweight ratio of the zeolite and the organic solvent is 1:5-30.

20. The process of any one of the previous solutions, wherein in thestep (5), the calcination temperature is 450-650° C., and thecalcination time is 1-4 hours.

21. The process of any one of the previous solutions, wherein theorganic solvent in step (3) and/or (4) has a water content of not morethan 5 wt %.

22. The process of any one of the previous solutions, wherein, theorganic solvent in step (3) and/or (4) has a water content of not morethan 3 wt %; and the Y zeolite obtained from the step (2) has a watercontent of not more than 3 wt %.

23. The process of any one of the previous solutions, wherein theorganic solvent is one or more of alkanes, aromatic hydrocarbons,alcohols, ketones, ethers, esters, halogenated alkanes such aschloridized alkanes.

24. The process of any one of the previous solutions, wherein theorganic solvent has a normal boiling point of 40-100° C.

25. The process of any one of the previous solutions, wherein theorganic solvent is preferably one or more of n-hexane, cyclohexane,heptane, benzene, toluene, methanol, ethanol, isopropanol, acetone,butanone, and trichloromethane.

26. A process for preparing a metal modified Y zeolite, comprising thesteps of:

(1) a Y-zeolite raw material is subjected to dewatering so that the rawmaterial has a water content by weight of not higher than 5%;

(2) the dewatered Y zeolite obtained from step (1) is contacted with amixture of a compound containing IVB group metal and an organic solvent,and the resulting mixture is optionally filtered and/or dried;

(3) the Y zeolite obtained from step (2) is calcined at 300-700° C.;

(4) the Y zeolite obtained from step (3) is contacted with an aqueousacid solution, and then calcined at 400-800° C. to produce themetal-modified Y zeolite containing the IVB group metal; the acidconcentration, as H+, is 0.1-2.0 mol/L.

27. The process of any one of the previous solutions, wherein in thestep (2), the mixing weight ratio of the compound containing IVB groupmetal, the Y zeolite and the organic solvent is 0.01-0.15:1:1-50,wherein the weight of the compound containing IVB group metal iscalculated as oxide, and the Y zeolite is calculated in a dry basis.

28. The process of any one of the previous solutions, wherein in thestep (2), the weight ratio of the compound containing IVB group metal(as oxide):the Y zeolite (dry basis):the organic solvent is0.01-0.1:1:5-30.

29. The process of any one of the previous solutions, wherein in thestep (2), the procedure of contacting the dewatered Y zeolite obtainedfrom step (1) with the compound containing IVB group metal and theorganic solvent and optionally filtering and/or drying comprises: thecompound containing IVB group metal, the organic solvent and the Yzeolite are mixed and contacted at a temperature in a range from roomtemperature to 100° C. for at least 0.5 hour, then optionally filtered,and then optionally dried.

30. The process of any one of the previous solutions, wherein in thestep (2), the procedure of contacting the dewatered Y zeolite obtainedfrom step (1) with the mixture of the compound containing IVB groupmetal and the organic solvent and optionally filtering and/or drying theresulting mixture is conducted once or more than once.

31. The process of any one of the previous solutions, wherein in thestep (3), the calcination temperature is 350-650° C., the calcinationtime is 2-4 hours, the calcination atmosphere is a dried air and/or aninert gas.

32. The process of any one of the previous solutions, wherein in thestep (4), the condition for contacting the Y zeolite obtained from step(3) and the aqueous acid solution comprises: the weight ratio(solid-to-liquid ratio) of the Y zeolite obtained from step (3) to theaqueous acid solution is 1:5-20, the contact temperature is in a rangefrom room temperature to 100° C., the contact time is at least 0.5 hour;the aqueous acid solution has an acid concentration, as H+, of 0.1-2mol/L.

33. The process of any one of the previous solutions, wherein theaqueous acid solution has an acid concentration, as H+, of 0.5-2 mol/L.

34. The process of any one of the previous solutions, wherein theorganic solvent is one or more of alkanes, aromatic hydrocarbons,alcohols, ketones, ethers, esters, halogenated alkanes such aschloridized alkanes.

35. The process of any one of the previous solutions, wherein theorganic solvent is selected from one or more of n-hexane, cyclohexane,heptane, benzene, toluene, methanol, ethanol, isopropanol, acetone,butanone, trichloromethane.

36. The process of any one of the previous solutions, wherein theorganic solvent has a normal boiling point of 40-100° C.

37. The process of any one of the previous solutions, wherein theorganic solvent has a water content of not more than 5 wt %.

38. The process of any one of the previous solutions, wherein theorganic solvent has a water content of not more than 1 wt %.

39. The process of any one of the previous solutions, wherein in thestep (2), the temperature for contacting the dewatered Y zeoliteobtained from step (1) and the mixture of the compound containing IVBgroup metal and the organic solvent is such a temperature that allowsthe organic solvent in a liquid state.

40. The process of any one of the previous solutions, wherein thecompound containing IVB group metal comprises a Ti-containing compoundand/or a Zr-containing compound.

41. The process of any one of the previous solutions, wherein theTi-containing compound is one or more of titanium sulfate, titanylsulfate, titanium tetrachloride, titanium trichloride, tetrabutyltitanate, ammonium fluotitanate, and the Zr-containing compound is oneor more of zirconium tetrachloride, zirconium sulphate, zirconiumnitrate, zirconium oxychloride, zirconium acetate, and zirconiumisopropoxide.

42. The process of any one of the previous solutions, wherein in thestep (1), the Y zeolite raw material is one or more of NaY zeolite, NaHYzeolite, NaNH₄Y zeolite, NH₄Y zeolite and HY zeolite.

43. The process of any one of the previous solutions, wherein in thestep (1), the Y zeolite raw material has a water content, afterdewatering, of not more than 1 wt %.

44. The process of any one of the previous solutions, wherein in thestep (4), the calcination is conducted in a 1-100% steam atmosphere.

45. The metal-modified Y zeolite of any one of Solutions 1-8, which isobtainable or obtained by the process of any one of Solutions 9-44.

46. A catalytic cracking catalyst, based on the total weight of thecatalyst, containing 10-60 wt % of a metal-modified Y zeolite, 10-60 wt% of a clay and 5-50 wt % of a binder, wherein said metal-modified Yzeolite is the metal-modified Y zeolite of any one of Solutions 1-8.

47. The catalytic cracking catalyst of Solution 46, wherein thecatalytic cracking catalyst contains 20-55 wt % of the IVB groupmetal-modified Y zeolite, 15-60 wt % of the clay and 10-40 wt % of thebinder.

48. The catalytic cracking catalyst of Solution 46 wherein the catalystfurther contains other molecular sieves commonly used in the catalyticcracking catalyst, said other molecular sieves include Y-type molecularsieves, MFI-structured molecular sieves, and SAPO molecular sieves.

49. The catalytic cracking catalyst of Solution 46, wherein, the contentof other molecular sieves commonly used in the catalytic crackingcatalyst is not more than 40 wt %, such as 1-35 wt %.

50. A method for preparing the catalytic cracking catalyst, whichcomprises the steps of preparing a metal-modified Y zeolite, mixing andslurrying the metal-modified Y zeolite and a clay and a binder, andspray-drying the resulting mixture, wherein said metal-modified Yzeolite is prepared according to the process of any one of Solutions9-44.

51. The method of Solution 50, wherein the clay is selected from one ormore of kaolin, halloysite, rectorite, diatomite, montmorillonite,bentonite and sepiolite; and the binder is selected from one or more ofhydrated alumina, alumina sol, pseudobohemite, bohemite, aluminamonohydrate, alumina trihydrate, and amorphous aluminum hydroxyde.

52. A solution according to any one of the above Solution 1-51, whereinthe metal-modified Y zeolite substantially does not contain one or moreof V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Ir, Ni, Pd, Pt, Cu, Zn, Ag,Au, Cd, Hg, Sc and Y.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a FT-IR spectra for a standard Y zeolite (Y) and themetal-modified Y zeolites prepared in Examples B.1.1.2, B.1.1.6 andB.1.2.4.

FIG. 2 is a ²⁷Al-NMR spectra for a standard Y zeolite (Y) and themetal-modified Y zeolites prepared in Examples B.1.1.2, B.1.2.2 andB.1.2.5.

DETAILED DESCRIPTION

Modified Zeolite

The first metal modified Y zeolite according to the present invention ischaracterized in that the ratio of the zeolite surface's IVB group metalcontent to the zeolite interior's IVB group metal content is not higherthan 0.2; e.g. 0.001-0.2; or 0.02-0.18.

The second metal modified Y zeolite according to the present inventionis characterized in that the ratio of the distortedtetrahedral-coordinated framework aluminum to thetetrahedral-coordinated framework aluminum in the zeolite latticestructure is (0.1-0.8):1; (0.2-0.8):1; (0.2-0.6):1; (0.1-0.6):1; or(0.2-0.5):1.

The third metal modified Y zeolite according to the present invention ischaracterized in that the ratio of the zeolite surface's IVB group metalcontent to the zeolite interior's IVB group metal content is not higherthan 0.2; e.g. 0.001-0.2; or 0.02-0.18; and the ratio of the distortedtetrahedral-coordinated framework aluminum to thetetrahedral-coordinated framework aluminum in the zeolite latticestructure is (0.1-0.8):1; (0.2-0.8):1; (0.2-0.6):1; (0.1-0.6):1; or(0.2-0.5):1.

The above three metal-modified Y zeolites are further characterized byone or more of the following features:

(1) the content of IVB group metal, as oxide and based on themetal-modified Y zeolite: 1-15 wt %, or 1-10 wt %;

(2) the specific surface area: 600-850 m²/g, 600-750 m²/g, or 630-730m²/g;

(3) the unit cell size (expressed as a0): 2.448-2.458 nm, 2.450-2.455nm; 2.449-2.455 nm; or 2.449-2.452 nm;

(4) the crystallinity: not less than 60%, e.g. 60-120%, or 60-95%; and

(5) the SiO₂/Al₂O₃ molar ratio: 5-50, 5-20, 5-8, 5-6

(6) the percent of the secondary pores (pore diameter of 6-20 nm) to thetotal secondary pores (pore diameter of 2-100 nm) being 30-50% or50%-65%, e.g. 35%, 40%, 45%, 50%, 55%, 60%.

According to the present invention, the IVB group metal is selected fromone or more of Ti, Zr, Hf, and Rf, e.g. one or more of Ti, Zr and Hf,preferably Ti and/or Zr.

According to the present invention, as oxide and by weight, themetal-modified Y zeolite has an anhydrous chemical composition formula,as oxide and by weight, of:

(0-2)Na₂O.(1-15)MO₂.(10-25)Al₂O₃(65-75)SiO₂, or

(0.1-1.2)Na₂O.(1-10)MO₂.(20-24)Al₂O₃.(67-74)SiO₂;

wherein M is a IVB group metal, selected from one or more of Ti, Zr, Hfand Rf.

In the metal-modified Y zeolite according to the present invention, mostof the IVB group metal ions are located in the interior of the zeolite,and a small amount of ions are present on the surface of the zeolite.The ratio of the zeolite surface's IVB group metal content to thezeolite interior's IVB group metal content is not higher than 0.2.

In the present invention, including the following Examples, the analysismethods for the zeolite are as follows:

The zeolite surface's IVB group metal content refers to the content ofthe IVB group metal which can be measured in the depth of 2-5 nm fromthe zeolite's surface by using X-ray Photoelectron Spectroscopy (XPS).The zeolite interior's IVB group metal content refers to the differencebetween the zeolite bulk's IVB group metal content and the zeolitesurface's IVB group metal content. The zeolite bulk's IVB group metalcontent is the content of IVB group metal in the zeolite that can beobtained through chemical analysis method.

The ratio of the distorted tetrahedral-coordinated framework aluminum tothe tetrahedral-coordinated framework aluminum refers to the ratio ofthe spectrum peak area at a chemical shift of 40 to that at a chemicalshift of 60, as measured by ²⁷Al MAS NMR.

Secondary pores are determined and measured according to the standardmethod RIPP151-90. A reference can be made to Analytical Methods inPetrochemical Industry (RIPP Experiment Techniques), Yang Cuiding et.al, Science Press, 1990.

The element content is determined by X-ray fluorescence spectrometry.

The specific surface area is determined by the BET method.

The unit cell size and the crystallinity are determined by X-raydiffraction according to the standard methods RIPP145-90 and RIPP146-90respectively. A reference can be made to Analytical Methods inPetrochemical Industry (RIPP Experiment Techniques), Yang Cuiding et.al, Science Press, 1990.

The SiO₂/Al₂O₃ molar ratio (i.e. framework Si/Al atom ratio) isdetermined according to the standard method SH/T0339-92.

Modified Zeolite Preparation Process

The present invention provides a process for preparing themetal-modified Y zeolite, comprising:

(1) a Y-zeolite raw material is subjected to dewatering so that the rawmaterial has a water content by weight of not higher than 5%;

(2) the dewatered Y zeolite obtained from step (1) is contacted with amixture of a compound containing IVB group metal and an organic solvent,and the resulting mixture is optionally filtered and/or dried;

(3) the Y zeolite obtained from step (2) is calcined at 300-700° C.,preferably for at least 0.5 hours, e.g. 0.5-5 hours;

(4) the Y zeolite obtained from step (3) is contacted with an aqueousacid solution, and then calcined at 400-800° C. in a 1-100% steamcondition for 0.5-5 hours to produce the metal-modified Y zeolitecontaining the IVB group metal; the acid concentration, as H⁺, is0.1-2.0 mol/L.

The metal-modified Y zeolite prepared by the above-mentioned process ischaracterized by one or more features selected from:

(1) most of the IVB group metal ions are located in the interior of thezeolite, while a small amount of ions are present on the zeolitesurface;

(2) the ratio of the zeolite surface's IVB group metal content to thezeolite interior's IVB group metal content is not higher than 0.2;

(3) the ratio of the zeolite surface's IVB group metal content to thezeolite interior's IVB group metal content is 0.001-0.2;

(4) the ratio of the zeolite surface's IVB group metal content to thezeolite interior's IVB group metal content is 0.02-0.18;

(5) the ratio of the distorted tetrahedral-coordinated frameworkaluminum to the tetrahedral-coordinated framework aluminum in thezeolite lattice structure is (0.2-0.8):1;

(6) the ratio of the distorted tetrahedral-coordinated frameworkaluminum to the tetrahedral-coordinated framework aluminum in thezeolite lattice structure is (0.2-0.6):1;

(7) the ratio of the distorted tetrahedral-coordinated frameworkaluminum to the tetrahedral-coordinated framework aluminum in thezeolite lattice structure is (0.1-0.6):1; and

(8) the ratio of the distorted tetrahedral-coordinated frameworkaluminum to the tetrahedral-coordinated framework aluminum in thezeolite lattice structure is (0.2-0.5):1.

Step (1): Dewatering

The Y zeolite raw material can be one or more of NaY zeolite, NH₄Yzeolite, HY zeolite, NaNH₄Y zeolite and NaHY zeolite, preferably NaYzeolite.

The NaY zeolite can by synthesized by crystallization. After removingthe mother liquor, the crystallized zeolite can be used in the presentinvention directly or after being washed. The NaY zeolite can becommercially available or can be prepared according to the method in theprior art, e.g. the method disclosed in U.S. Pat. No. 3,671,191.

The NaNH₄Y zeolite is one obtained by exchanging NaY zeolite with NH₄ ⁺to a certain extent.

The NaHY zeolite can be obtained by calcining the NaNH₄Y zeolite or byexchanging the NaY zeolite with H⁺ to a certain extent.

The dewatering is preferably conducted at a temperature of not more than400° C. The dewatering can be done by drying or calcining. The dryingcan be a conventional drying method or a vacuum drying method. Uponusing the calcination to dewater, the calcination temperature ispreferably not more than 400° C., e.g. 200-400° C., usually 250-350° C.The conventional drying method includes heat-drying, air-drying,flash-drying, or spray-drying. The drying temperature is usually nothigher than 200° C., e.g. 80-200° C. The dewatered zeolite preferablyhas a water content of not higher than 3 wt %, preferably not higherthan 1 wt %.

Step (2): Contact-Optional Filtering-Optional Drying

In the step (2), the dewatered Y zeolite obtained from the step (1) iscontacted with a mixture of a compound containing IVB group metal and anorganic solvent to introduce the modifying metal into the zeolite.

The contacting process comprises mixing and slurrying a mixture of acompound containing IVB group metal and an organic solvent and the Yzeolite, and being subjected to an ion exchange at the exchangetemperature (or the contact temperature).

After the contact, a filtering is optionally conducted. Then, a dryingis optionally conducted.

The contact can be done once or more than once. The so-called “more thanonce” contact means the zeolite obtained from the previous treatment iscontacted with a mixture of an organic solvent and a compound of themodifying metal; and after each contact, the filtering is optionallydone, and the drying is optionally done. In the case of “more than once”contact, it is preferable to dry after the last contact. In the case of“more than once” contact, the Y zeolite obtained through filtering canbe treated directly with a compound containing IVB group metal and anorganic solvent, or can be dried and/or calcined, and then treated witha compound containing IVB group metal and an organic solvent.

There can be at least one temperature point in the exchange temperaturerange, at which point the solvent can be present in a liquid state.

In each contact, the weight ratio of the compound containing IVB groupmetal (as oxide):Y zeolite (dry basis):the organic solvent is(0.01-0.15):1:(1-50), or (0.01-0.14):1:(5-30), or (0.02-0.11):1:(5-25),or (0.01-0.1):1:(5-30).

The contact time for example is at least 0.5 hour, e.g. 0.5-5 hours, or1.5-3.5 hours.

The contact temperature can be such a temperature, at which the organicsolvent is in a liquid state.

The exchange temperature can be such a temperature range, in which theorganic solvent is in a liquid state. Usually, the exchange temperaturecan be a temperature range, the lower point of which is higher than thesolidifying point of the organic solvent, and the upper point of whichis lower than the boiling point of the organic solvent. For example, theexchange temperature is, from the room temperature to a temperaturewhich is 20° C. lower than the normal boiling point of the organicsolvent; from 0 to 100° C.; from room temperature to 100° C.; from 0 to100° C. and 20° C. lower than the normal boiling point of the organicsolvent; and from room temperature to 100° C. and 20° C. lower than thenormal boiling point of the organic solvent. The room temperature is15-40° C. The normal boiling point means the boiling point at 1 atm.

The drying temperature is usually not more than 200° C., e.g. 0-200° C.,from room temperature to 150° C., from room temperature to 120° C., from100 to 120° C.

The drying time can be 4-48 hours, 12-48 hours.

The IVB group metal can be one or more of Ti, Zr and Hf, preferably Tiand/or Zr. The compound containing IVB group metal can be one or more ofcompounds containing Ti and/or Zr, e.g. a Ti-containing compound, aZr-containing compound or a Ti- and Zr-containing compound. The compoundcontaining IVB group metal is preferably soluble in the used organicsolvent, for example, its solubility in the organic solvent is not lessthan 0.1 g of the compound containing IVB group metal/100 g of theorganic solvent. The Ti-containing compound can be one or more oftitanium sulfate, titanyl sulfate, titanium tetrachloride, titaniumtrichloride, tetrabutyl titanate, and ammonium fluotitanate, theZr-containing compound can be one or more of zirconium tetrachloride,zirconium sulphate, zirconium nitrate, zirconium oxychloride, zirconiumacetate, and zirconium isopropoxide.

The organic solvent has a water content of not more than 5 wt %,preferably not more than 1 wt %, e.g. not more than 0.1 wt %, not morethan 0.01 wt %, or not more than 0.001 wt %. Preferably, in the organicsolvent, the content of the organic substance as solvent is not lessthan 95 wt %, preferably not less than 99 wt %. The organic solvent canbe one or more of alkanes, aromatic hydrocarbons, alcohols, ketones,ethers, esters, halogenated alkanes such as chloridized alkanes. Thenormal boiling point of the organic solvent (1 atm) is preferably40-100° C., which is both favorable for the dispersion of the metalcomponent, and favorable for removing the organic solvent. The organicsolvent can be, for example, one or more of n-hexane, cyclohexane,heptane, benzene, toluene, methanol, ethanol, isopropanol, acetone,butanone and trichloromethane.

Step (3): Calcination

The calcination temperature can be for example 300-700° C., 350-650° C.,400-620° C., or 450-600° C.

The calcination time can be for example 0.5-5 hours, 1-5 hours, 2-4hours.

The calcination atmosphere can be for example a dried air, and/or aninert gas atmosphere, preferably an inert gas atmosphere.

The inert gas can be nitrogen and/or helium. In case of the dried air,the water content therein is below 1 vol %, e.g. below 0.5 vol %.

Step (4): Acid Treatment-Calcination

The temperature for contacting the aqueous acid solution with theY-zeolite obtained from the step (3) is in a range from room temperatureto 100° C., e.g. 75-95° C.

The contact time is not less than 0.2 hour, e.g. 0.5-5 hours, Thecontact solid-to-liquid ratio (the weight ratio of zeolite to theaqueous acid solution) is 1:5-20, e.g. 1:6-14.

The concentration of the used aqueous acid solution, as H⁺, is 0.1-2mol/L, 0.5-2 mol/L, 0.5-1.5 mol/L. After contact, the filtering is done.After filtering, the acid-contacted zeolite is washed with water toremove free acid, and then dried and calcined. The calcinationtemperature is 400-800° C., 500-600° C. The calcination atmosphere is a1-100% steam condition. The calcination time is 0.5-5 hours, or 1-3hours. The acid used in the step (4) is selected from one or more ofhydrochloric acid, sulfuric acid, nitric acid, oxalic acid, acetic acid,formic acid, preferably one or more of hydrochloric acid, oxalic acid,and formic acid.

In another aspect, the present invention provides a process forpreparing the metal-modified Y zeolite, which comprises:

(1) a Y zeolite is treated by contacting with an acid solution and/or anaqueous EDTA solution; wherein said acid is an organic acid and/or aninorganic acid;

(2) the product obtained from the step (1) is dewatered at a temperaturebelow 400° C., so that the water content in the zeolite is not higherthan 5 wt %;

(3) the zeolite obtained from the step (2) is impregnated with a metalin an organic solvent;

(4) the metal impregnated Y zeolite obtained from the step (3) and anorganic solvent are added to a vessel at a solid-to-liquid weight ratioof 1:5-50, an inert gas such as nitrogen and/or helium is introduced tothe vessel, and the vessel is kept under a pressure of 0-2.0 MPa (gaugepressure) at a temperature in the range from room temperature to 200° C.for at least one hour, e.g. 1-48 hours; filtering and/or drying isoptionally conducted, and filtering and drying are preferably conducted;

(5) the zeolite obtained from the step (4) is calcined; the calcinationis conducted in an inert gas atmosphere, the calcination temperature is300-700° C., the calcination time is 0.5-5 hours, or more than 0.5 hour.

The metal-modified Y zeolite prepared by the above-mentioned process ischaracterized by one or more features selected from:

(1) most of the IVB group metal ions are located in the interior of thezeolite, while a small amount of ions are present on the zeolitesurface;

(2) the ratio of the zeolite surface's IVB group metal content to thezeolite interior's IVB group metal content is not higher than 0.2;

(3) the ratio of the zeolite surface's IVB group metal content to thezeolite interior's IVB group metal content is 0.001-0.2;

(4) the ratio of the zeolite surface's IVB group metal content to thezeolite interior's IVB group metal content is 0.02-0.18;

(5) the ratio of the distorted tetrahedral-coordinated frameworkaluminum to the tetrahedral-coordinated framework aluminum in thezeolite lattice structure is (0.2-0.8):1;

(6) the ratio of the distorted tetrahedral-coordinated frameworkaluminum to the tetrahedral-coordinated framework aluminum in thezeolite lattice structure is (0.2-0.6):1;

(7) the ratio of the distorted tetrahedral-coordinated frameworkaluminum to the tetrahedral-coordinated framework aluminum in thezeolite lattice structure is (0.1-0.6):1; and

(8) the ratio of the distorted tetrahedral-coordinated frameworkaluminum to the tetrahedral-coordinated framework aluminum in thezeolite lattice structure is (0.2-0.5):1.

Step (1): Contact

The Y zeolite as starting material can be one or more of NaY, NaHY,NaNH₄Y, NH₄Y, HY, USY, once-exchanged-once-calcined Y zeolite, DASYzeolite, twice-exchanged-twice-calcined Y zeolite,twice-exchanged-once-calcined Y zeolite.

The once-exchanged-once-calcined Y zeolite for example can be the Yzeolite obtained by subjecting a NaY zeolite toonce-exchanging-once-calcination; DASY zeolite for example can be the Yzeolite obtained by subjecting a Y zeolite to calcination in presence ofsteam; The twice-exchanged-twice-calcined Y zeolite for example can bethe Y zeolite obtained by subjecting a NaY zeolite totwice-exchanging-twice-calcination; The twice-exchanged-once-calcined Yzeolite for example can be the Y zeolite obtained by subjecting a NaYzeolite to twice-exchanging-once-calcination; and preferably, theexchange is conducted with H⁺ and/or NH₄ ⁺. The weight ratio between theY zeolite (dry basis) and the acid solution (the aqueous acid solution)or the aqueous EDTA solution (the solid-to-liquid ratio) is 1:5-20. Thecontact temperature is in a range from room temperature to 100° C. Thecontact time is at least 0.5 hour, e.g. 0.5-3 hours. After the contact,the filtering and washing can be done. The acid concentration of theacid solution, as H⁺, is 0.1-1 mol/L, 0.2-0.5 mol/L or 0.5-1 mol/L. Theacid can be an inorganic acid and/or an organic acid. The inorganic acidcan be one or more of hydrochloric acid, sulfuric acid and nitric acid;the organic acid can be one or more of formic acid, acetic acid, oxalicacid, citric acid. In the step (1), the washing can be done with watersuch as deionized water and distillated water to remove the acid in thezeolite. For example, the weight ratio of water to zeolite can be5-20:1. The treated zeolite obtained from the step (1) has a Na₂Ocontent of not higher than 4.0 wt % and preferably not higher than 2.0wt %.

Step (2)—Calcination

The treated zeolite obtained from the step (1) can be calcined to removethe adsorbed water. Through the calcination, the water content in thezeolite is not higher than 5 wt %, for example not higher than 3 wt %.

The calcination temperature can be 200-400° C., e.g. 300-350° C.

The calcination time can be 2-10 hours, e.g. 2-4 hours.

The solid content of the calcined zeolite is not less than 95 wt %, notless than 97 wt %, or 97-99.9 wt %.

Step (3)

The zeolite being impregnated with a metal in an organic solventcomprises mixing the compound containing IVB group metal in the organicsolvent and the zeolite, and keeping the mixture for at least 0.5 hours,e.g. 0.5-12 hours with stirring or without stirring (by standing). Forexample, the mixture was kept with stirring for 0.5-12 hours. Then, thenext step can be conducted, for example, by proceeding with the step(4), or repeating the step (3). The introduction of modifying metal(s)into the Y zeolite can be done through one or more than oneimpregnations. The solid-to-liquid weight ratio of the Y zeolite to theorganic solvent can be 1:(0.5-5), 1:(1-2), 1:(1-4), or 1:(1.1-1.6). Theimpregnation temperature is one that can make the organic solvent be ina liquid state. The impregnation can be done in a manner of isometricimpregnation or excessive impregnation. The impregnation temperature isnot particularly limited, for example, the impregnation can be done atroom temperature.

The IVB group metal is selected from one or more of Ti, Zr, Hf and Rf,preferably Ti and/or Zr. The compound containing IVB group metal can beone or more of a Ti-containing compound, a Zr-containing compound, aHf-containing compound, a Rf-containing compound, e.g. a Ti-containingcompound and/or a Zr-containing compound. The compound containing IVBgroup metal can be an inorganic salt and/or an organometallic compoundof IVB group metal, for example, the Ti-containing compound can be oneor more of titanium sulfate, titanyl sulfate, titanium tetrachloride,titanium trichloride, tetrabutyl titanate, and ammonium fluotitanate.The Zr-containing compound can be one or more of zirconiumtetrachloride, zirconium sulphate, zirconium nitrate, zirconiumoxychloride, zirconium acetate, and zirconium isopropoxide.

The organic solvent has a water content of not higher than 5 wt %, ornot higher than 3 wt %, or not higher than 1 wt %. The organic solventcan be one or more of alkanes, aromatic hydrocarbons, alcohols, ketones,ethers, esters, halogenated alkanes such as chloridized alkanes. Theorganic solvent can have a normal boiling point of 40-100° C. Theorganic solvent is preferably one or more of n-hexane, cyclohexane,heptane, benzene, toluene, methanol, ethanol, isopropanol, acetone,butanone, trichloromethane.

Step (4) Introducing an Inert Gas-Optional Filtering-Optional Drying

The impregnated zeolite and the organic solvent are placed in a reactionvessel such as autoclave.

The solid-to-liquid weight ratio of the zeolite to the organic solventis 1:(5-50), e.g. 1:(5-30) or 1:(5-10). Generally, the organic solventused in the step (4) is identical to that used in the step (3). An inertgas such as nitrogen and helium can be introduced to the reactionvessel. The reaction vessel pressure (gauge pressure) is 0.0-2.0 MPa, or0.5-1.5 MPa. The reaction vessel temperature is from room temperature to200° C., from room temperature to 150° C., or from room temperature to90° C. The substances in the reaction vessel can be kept by standing orunder stirring for at least 1 hour, usually 1-48 hours, 2-24 hours, or4-24 hours.

Then, the filtering and/or drying can be optionally conducted. Thefiltering and the drying are preferably conducted so that the zeolitecan be separated from the organic solvent. The filtering and the dryingcan be conventionally conducted. The existing drying process can beadopted, such as air-drying, flash-drying and spray-drying. For example,the drying temperature can be 100-200° C. For example, the drying timecan be 1 second to 2 days, e.g. 6-24 hours.

Step (5) Calcination

The zeolite obtained from the step (4) is calcined; the calcination isconducted in an inert gas atmosphere, the calcination temperature is300-700° C., the calcination time is 0.5-5 hours, or more than 0.5 hour.

The calcination is conducted in an inert gas atmosphere. The calcinationtemperature is 300-700° C., 450-650° C. or 500-600° C. The calcinationtime is 0.5-5 hours, or 1-4 hours. The inert gas comprises one or moreof nitrogen and helium.

Catalytic Cracking Catalyst

The present invention further provides a catalytic cracking catalyst,based on the total weight of the catalyst, containing 20-60 wt % of theIVB group metal modified Y zeolite according to the present invention,10-60 wt % of a clay and 5-50 wt % of a binder.

Method for Preparing Catalytic Cracking Catalyst

The present invention also provides a method for preparing the catalyticcracking catalyst, which comprises the steps of mixing and slurrying themetal-modified Y zeolite according to the present invention and a clayand a binder, and spray-drying the resulting mixture. For example,deionized water, the clay and the binder can be mixed and slurried, andto the resulting slurry is added the modified Y zeolite. The technologyof spray-drying and calcination are well known in the prior art, andtherefore would not be discussed in detail.

According to the present invention, the clay is selected from one ormore of kaolin, halloysite, rectorite, diatomite, montmorillonite,bentonite, and sepiolite, which are well known in the art.

According to the present invention, the binder refers to a substance,which can form a heat-resistant inorganic oxide after calcination. Theheat resistant inorganic oxide comprises one or more of alumina, silica,amorphous silica-alumina, preferably alumina. The binder is preferablyselected from one or more of hydrated alumina, alumina sol,pseudobohemite, bohemite, alumina trihydrate, alumina monohydrate, andamorphous aluminum hydroxide. These different binders can transfer tothe form of γ-Al₂O₃ after calcination. These binders are well known inthe art.

The IVB metal-modified Y zeolite according to the present invention hashigh crystallinity, large specific surface area, and high thermal andhydrothermal stability.

According to the present invention, Y zeolite is modified with the IVgroup metal, without using the costly rare earth material. And themodified Y zeolite according to the present invention can provide acomparable or better thermal and hydrothermal stability than the rareearth modified Y zeolite.

The modified Y zeolite according to the present invention can be used inthe catalytic cracking catalyst to substitute the rare-earth modified Yzeolite. The catalyst cost can be remarkably reduced.

The catalytic cracking catalyst according to the present invention showsexcellent performance in cracking activities, gasoline yield, and cokeselectivity.

Example

In the following Examples, the used room temperature is 15-40° C. suchas 26° C.

The light oil micro-activity (MA) is measured according to the standardmethod RIPP92-90, wherein 5 g of the catalyst is used. The reactiontemperature is 460° C. The feedstock is a straight run light dieselhaving a distillation range of 235-337° C. The product composition isanalyzed by gas chromatography. According to the product composition,the micro-activity is calculated, as follows:

light oil micro-activity (MA)=(the gasoline output (<216° C.)+gasoutput+coke output)/feedstock input×100%

In the Examples and Comparative Examples, the used starting materialsare commercially available and their detailed specifications are asfollows.

Zeolite raw materials, industrial product, available from SinopecCatalyst Company, Qilu Division.

ReCl₃ (Mixed rare earth chloride), industrial grade, available fromSinopec Catalyst Company, Qilu Division.

Other Agents: Chemically pure, unless indicated to the contrary

The secondary pore volume is measured according to the standard methodRIPP151-90. A reference can be made to Analytical Methods inPetrochemical Industry (RIPP Experiment Techniques), Yang Cuiding et.al, Science Press, 1990. According to the adsorption isotherm, the totalpore volume of the zeolite is measured. Then the micro-pore volume ofthe zeolite is measured from the adsorption isotherm according to the Tplotting method. The total pore volume minus the micro-pore volumeleaves the secondary pore volume, and the percent of the secondary pores(pore diameter of 6-20 nm) to the total secondary pores (pore diameterof 2-100 nm) is calculated from the secondary pore distribution of thezeolite.

A.1 Zeolite Modification Example A.1.1.1

200 g of NaY zeolite was calcined at 300° C. for 3 hours (aftercalcination, the water content was 1 wt %). After being cooled to roomtemperature, it was placed in 2000 g of ethanol (the ethanolcontent=99.9 wt %). The resulting slurry was stirred homogenously. Tothe slurry was added 10.5 g of zirconium nitrate (Zr(NO₃)₄.5H₂O). Then,the resulting mixture was stirred at room temperature for 2 hours, andfiltered. The filter cake was dried in a baker at 100° C. for 24 hours,and then calcined at 600° C. for 2 hours.

The above calcined Y zeolite was added to 2000 g of an aqueous inorganicacid solution with an acid concentration of 1.0 mol/L (a dilutedhydrochloric acid solution). The resulting mixture was mixedhomogenously, stirred at 80° C. for 3 hours, then filtered, washed withdeionized water (the weight of washing water was 15 times larger thanthe dry basis weight of the zeolite), and filtered. The filter cake wasremoved, and calcined in a 100% steam at 600° C. for 1 hour. Finally,the Zr-modified zeolite was obtained and named as Zr(2)Y, the propertiesof which were shown in Table A1.

Example A.1.1.2

200 g of NaY zeolite was vacuumized at 200° C. under 0.001 Pa for 4hours. After being cooled to room temperature (water content=0.5 wt %),it was placed in 1500 g of ethanol (ethanol content=99.9 wt %). Theresulting slurry was stirred homogenously. To the slurry was added 15.7g of zirconium oxychloride (ZrOCl₂.8H₂O). Then, the resulting mixturewas stirred at room temperature for 3 hours, and filtered. The filtercake was dried in a baker at 100° C. for 24 hours, and then calcined at500° C. for 3 hours.

The above calcined Y zeolite was added to 1500 g of an aqueous oxalicacid solution with an acid concentration of 2.0 mol/L. The resultingmixture was mixed homogenously, warmed upto 90° C., stirred for 1 hour,then filtered, and washed with deionized water (the weight of washingwater was 15 times larger than the dry basis weight of the zeolite). Thefilter cake was removed, and calcined in a 100% steam at 500° C. for 2hour. Finally, the Zr-modified zeolite was obtained and named as Zr(4)Y,the properties of which were shown in Table A1.

Example A.1.1.3

200 g of NaY zeolite was calcined at 300° C. for 3 hours. After beingcooled to room temperature (water content=1 wt %), it was placed in 1000g of n-hexane (n-hexane content=99.5 wt %). The resulting slurry wasstirred homogenously. To the slurry was added 37.8 g of zirconiumisopropoxide. The resulting mixture was stirred at room temperature for3 hours, and filtered. The filter cake was dried in a baker at 120° C.for 48 hours, and then calcined at 500° C. (in a dried air atmosphere,the water content in the air was not more than 0.2 vol %) for 4 hours.

The above calcined Y zeolite was added to 1000 g of an aqueous inorganicacid (sulfuric acid) solution with an acid concentration of 0.5 mol/L.The resulting mixture was stirred at 80° C. for 3 hours, then filtered,and washed with deionized water (the weight of washing water was 20times larger than the dry basis weight of the zeolite). The filter cakewas removed, and calcined at 500° C., under a 100% steam atmosphere for3 hours. Finally, the Zr-modified zeolite was obtained and named asZr(8)Y, the properties of which were shown in Table A1.

Example A.1.1.4

200 g of NaY zeolite was calcined at 300° C. for 3 hours. After beingcooled to room temperature, it was placed in 1000 g of butanone(butanone content=99.5 wt %). The resulting slurry was stirredhomogenously. To the slurry was added 14.2 g of titanium tetrachloride.The resulting mixture was stirred at room temperature for 2 hours, andfiltered. The filter cake was dried in a baker at 120° C. for 24 hours,and then calcined at 450° C. in a nitrogen atmosphere for 4 hours.

The above calcined Y zeolite was added to 1000 g of an aqueous inorganicacid (hydrochloric acid) solution with an acid concentration of 0.5mol/L. The mixture was mixed homogenously, stirred at 80° C. for 2hours, then filtered, and washed with deionized water (the weight ofwashing water was 10 times larger than the dry basis weight of thezeolite). The filter cake was removed, and calcined at 500° C. in a 100%steam atmosphere for 2 hours. Finally, the Ti-modified zeolite wasobtained and named as Ti(4)Y, the properties of which were shown inTable A1.

Example A.1.1.5

200 g of NaY zeolite was vacuumized at 300° C. under 0.001 Pa for 4hours. After being cooled to room temperature, it was placed in 2000 gof cyclohexane (cyclohexane content=99.9 wt %). The resulting slurry wasstirred homogenously. To the slurry was added 63.9 g of tetrabutyltitanate. The resulting mixture was stirred at room temperature for 3hours, and filtered. The filter cake was dried at 100° C. in a baker for48 hours, and then calcined at 600° C. in a nitrogen atmosphere for 2hours.

The above calcined Y zeolite was added to 2000 g of an aqueous oxalicacid solution with an acid concentration of 1.5 mol/L. The mixture wasmixed homogenously, stirred at 90° C. for 1 hour, then filtered, andwashed with deionized water (the weight of washing water was 20 timeslarger than the dry basis weight of the zeolite). The filter cake wasremoved, and calcined at 600° C. in a 100% steam atmosphere for 2 hours.Finally, the Ti-modified zeolite was obtained and named as Ti(10)Y, theproperties of which were shown in Table A1.

Example A.1.1.6

200 g of NaY zeolite was vacuumized at 300° C. under 0.001 Pa for 4hours. After being cooled to room temperature, it was placed in 3000 gof ethanol (ethanol content=99.9 wt %). The resulting slurry was stirredhomogenously. To the slurry were added 3.6 g of titanium tetrachlorideand 31.5 g of zirconium nitrate. The resulting mixture was stirred atroom temperature for 3 hours, and filtered. The filter cake was dried at100° C. in a baker for 48 hours, and then calcined at 550° C. in anitrogen atmosphere for 3 hours.

The above calcined Y zeolite was added to 3000 g of an aqueous inorganicacid (nitric acid) solution with an acid concentration of 1.0 mol/L. Themixture was mixed homogenously, stirred at 80° C. for 2 hours, thenfiltered, and washed with deionized water (the weight of washing waterwas 20 times larger than the dry basis weight of the zeolite). Thefilter cake was removed, and calcined at 550° C. under a 100% steamatmosphere for 3 hours. Finally, the Ti- and Zr-modified zeolite wasobtained and named as Ti—Zr—Y, the properties of which were shown inTable A1.

Example A.1.1.7

A modified zeolite was prepared according to Example A.1.1.4, exceptthat after being treated with the inorganic acid, the filter cake wasfirstly dried, and then calcined at 500° C. in an air atmosphere toproduce the modified zeolite named as Ti(4)Y-1.

Example A.1.2.1

200 g of NaY zeolite and 2000 g of deionized water were mixed andslurried. To the resulting slurry was added 45 mL of a solution of 270g/l RECl₃. The mixture was adjusted with a diluted hydrochloric acid topH=3.8, and warmed upto 80° C. to exchange for 1 hour. After filteringand washing, the resulting filter cake was calcined at 500° C. for 3hours. Then, the resulting Y zeolite and 2000 g of deionized water weremixed and slurried. To the slurry was added 45 g of ammonium sulfate.The mixture was adjusted with a diluted hydrochloric acid to pH=4.0, andwarmed upto 80° C. to exchange for 1 hour. After filtering and washing,the resulting filter cake was calcined at 600° C., under a 100% steamatmosphere for 3 hours. Finally, a RE-modified zeolite was obtained andnamed as RE(8)Y, the properties of which were shown in Table A1.

Example A.1.2.2

200 g of NaY zeolite was placed in 2000 g of deionized water. Theresulting slurry was stirred homogenously. To the slurry was added 31.4g of zirconium oxychloride ZrOCl₂.8H₂O. The mixture was warmed upto 90°C., stirred for 3 hours, and filtered. The filter cake was dried at 100°C. in a baker for 12 hours, and calcined at 500° C. for 3 hours. Thenthe calcined Y zeolite and 2000 g of deionized water were mixed andslurried. To the resulting slurry was added 45 g of ammonium sulfate.The mixture was adjusted with a diluted hydrochloric acid to pH=4.0, andwarmed upto 80° C. to exchange for 1 hour. After filtering and washing,the filter cake was calcined at 500° C. in a 100% steam atmosphere for 2hours. Finally, the Zr-modified zeolite was obtained and named asZr(W)Y, the properties of which were shown in Table A1.

Example A.1.2.3

A modified zeolite was prepared according to Example A.1.2.2, exceptthat 14.2 g of titanium tetrachloride was used in place of 31.4 g ofzirconium oxychloride ZrOCl₂.8H₂O. Finally, the Ti-modified zeolite wasobtained and named as Ti(W)Y, the properties of which were shown inTable A1.

Example A.1.2.4

A Zr-modified Y zeolite was prepared according to Example 1 ofCN101134576A. Finally, the Zr-modified zeolite was obtained and named asZr(G)Y, the properties of which were shown in Table A1.

Example A.1.2.5

200 g of NH₄USY (Si/Al atom ratio=5.2) was added to 500 g of absoluteethanol under a violent stirring to form a suspension, to which wasadded 50 g/L of a solution of butyl titanate-absolute ethanol (as TiO₂)under a violent stirring. The mixture was air-dried overnight understirring. The resulting sample was calcined at 500° C. for 5 hours toproduce Ti-modified zeolites with titanium content of 2.4 wt % and 9.1wt %, named as DT2 and DT9.

TABLE A1 Physical and chemical properties of metal-modified Y zeolitesExample A.1.1.X 1 2 3 4 5 6 7 Sample Zr(2)Y Zr(4)Y Zr(8)Y Ti(4)Y Ti(10)YTi—Zr—Y Ti(4)Y-1 α0, nm 2.452 2.450 2.449 2.451 2.449 2.449 2.455crystallinity, % 77.6 73.7 70.3 72.6 69.1 68.8 73.0 Na₂O, wt % 1.0 0.90.7 0.9 0.8 1.0 0.9 Al₂O₃, wt % 22.8 22.5 21.8 22.8 21.3 20.9 22.8 SiO₂,wt % 73.6 72.5 69.7 72.1 68.8 70.5 72.0 ZrO₂, wt % 2.1 3.8 7.3 0 0 5.5 0TiO₂, wt % 0 0 0 3.7 8.6 1.9 3.7 RE₂O₃, wt % 0 0 0 0 0 0 0 specificsurface area, m²/g 676 710 690 726 702 640 722 lattice collapsetemperature, ° C. 1048 1044 1051 1046 1050 1051 1045 the ratio of thezeolite surface's IVB group 0.05 0.10 0.12 0.08 0.16 0.15 0.10 metalcontent to the zeolite interior's IVB group metal content the ratio ofthe distorted 0.4 0.3 0.5 0.4 0.6 0.5 0.3 tetrahedral-coordinatedframework aluminum to the tetrahedral-coordinated framework aluminum Thepercent of the secondary pores (pore 48.2 50.6 57.8 52.4 62.4 64.5 51.8diameter of 6-20 nm) to the total secondary pores (pore diameter of2-100 nm) Example A.1.2.X 1 2 3 4 5 Sample RE(8)Y Zr(W)Y Ti(W)Y Zr(G)YDT2 DT9 α0, nm 2.451 2.450 2.452 2.451 2.458 2.448 crystallinity, % 62.750.6 53.9 64.2 69.9 63.0 Na₂O, wt % 1.0 0.8 1.0 0.8 1.1 1.2 Al₂O₃, wt %21.7 21.9 21.8 20.8 21.2 21.8 SiO₂, wt % 70.5 69.9 72.8 70.7 74.8 67.2ZrO₂, wt % 0 7.0 0 7.5 0 0 TiO₂, wt % 0 0 3.9 0 2.4 9.1 RE₂O₃, wt % 6.60 0 0 0 0 specific surface area, m²/g 640 548 526 624 535 520 latticecollapse temperature, ° C. 1043 1028 1015 1030 1036 1036 the ratio ofthe zeolite surface's IVB group metal — 1.8 1.2 — 1.0 1.3 content to thezeolite interior's IVB group metal content the ratio of the distortedtetrahedral-coordinated — 0.05 0.06 0.02 0.01 0.04 framework aluminum tothe tetrahedral-coordinated framework aluminum

A.2 Stability of the Modified Zeolite

Modified Y zeolites prepared according to Examples A.1.1.1-A.1.1.7 andA.1.2.1-A.1.2.5 were aged at 800° C. under a 100% steam condition for 8hours to determine the crystallinity and the specific surface area, andthe crystallinity retention and the specific surface area retention werecalculated. The results were listed in Table A2. The aged zeolites weresubjected to the light oil micro-activity (MA) test. The results werelisted in Table A2.

TABLE A2 Physical and chemical properties of the metal-modified Yzeolites after the hydrothermal aging Example A.2.1.X 1 2 3 4 5 6 7 Yzeolite Zr(2)Y Zr(4)Y Zr(8)Y Ti(4)Y Ti(10)Y Ti—Zr—Y Ti(4)Y-1Crystallinity retention, % 60.5 62.1 64.7 63.9 65.9 66.3 63.2 Specificsurface area retention, % 62.4 65.0 66.7 64.1 67.8 68.0 65.2 800° C./8h, activity 81 84 86 85 86 87 84 Example A.2.2.X 1 2 3 4 5 Y zeoliteRE(8)Y Zr(W)Y Ti(W)Y Zr(G)Y DT2 DT9 Crystallinity retention, % 63.2 45.550.2 60.8 60.2 62.0 Specific surface area retention, % 65.5 50.8 51.664.9 61.6 62.9 800° C./8 h, activity 84 75 75 80 70 72

Example A.2.1.8

According to Example A.1.1.5, Ti-modified Y zeolites having Ti contents(as TiO₂) of 1 wt %, 2 wt %, 7 wt %, 12 wt %, 15 wt % were prepared. Thephysical and chemical properties were listed in Table A3. TheseTi-modified Y zeolites were aged at 800° C. under a 100% steam conditionfor 8 hours to determine the crystallinity and the specific surfacearea, and the crystallinity retention and the specific surface arearetention were calculated. The aged zeolites were subjected to the lightoil micro-activity (MA) test. The results were listed in Table A3.

Example A.2.2.6

According to Example A.1.2.1, RE-modified Y zeolites having RE contentsof 1 wt %, 2 wt %, 12 wt %, 15 wt % were prepared. The physical andchemical properties were listed in Table A3. These RE-modified Yzeolites were aged at 800° C. under a 100% steam condition for 8 hoursto determine the crystallinity and the specific surface area, and thecrystallinity retention and the specific surface area retention werecalculated. The aged zeolites were subjected to the light oilmicro-activity (MA) test. The results were listed in Table A3.

TABLE A3 Example A.2.1.8 Example A.2.2.6 TiO₂, wt % 1.0 2.0 7.0 12.015.0 0 0 0 0 RE₂O₃, wt % 0 0 0 0 0 1.0 2.0 12.0 15.0 Na₂O, wt % 1.1 0.91.1 0.9 0.9 0.8 1.0 1.0 0.9 Al₂O₃, wt % 23.2 22.8 21.4 19.2 16.5 22.021.8 20.2 17.2 SiO₂, wt % 73.3 72.8 68.7 66.9 67.1 74.5 73.5 66.0 66.2α0, nm 2.449 2.450 2.452 2.455 2.455 2.455 2.457 2.458 2.460Crystallinity, % 71.2 70.6 72.8 71.1 69.8 70.2 68.4 62.2 60.8 specificsurface 674 680 690 666 645 620 653 560 490 area, m²/g Lattice collapse1042 1045 1050 1046 1046 1030 1044 1045 1045 temperature, ° C. the ratioof the 0.02 0.05 0.12 0.15 0.17 zeolite surface's IVB group metalcontent to the zeolite interior's IVB group metal content Zeolite No.Ti(1)Y Ti(2)Y Ti(7)Y Ti(12)Y Ti(15)Y After the hydrothermal agingCrystallinity 62.2 61.2 63.6 66.0 64.5 60.0 63.4 66.2 65.0 retention, %Specific surface 61.9 63.8 63.4 67.7 66.6 62.2 64.5 67.0 65.9 arearetention, % 800° C./8 h, 82 85 87 85 85 80 82 83 83 activity

A.3 Catalyst Example A.3.1.1

The modified Y zeolite prepared according to the present invention,Zr(8)Y, was used as active component to prepare the catalyst accordingto the conventional preparation method of the catalytic crackingcatalyst. The preparation was as follows. According to the ratio ofzeolite (dry basis):kaolin (dry basis):pseudobohemite (as Al₂O₃):aluminasol (as Al₂O₃) being 38:34:20:8, kaolin and decationized water weremixed and slurried. To the resulting slurry was added alumina sol, andfurther added pseudoboehmite under a continuous stirring. After 30minutes of stirring, a liquor containing zeolite was added to thecolloid. The resulting mixture was mixed homogenously, spray-dried andshaped to produce a catalyst, named as C1.

The catalyst was pretreated at 800° C. in a 100% steam condition for 17hours. Then the pretreated catalyst was tested on a small-scale fixedfluidised bed (ACE) for catalyst evaluation.

The feedstock for evaluation was Wuhun III, the properties of which wereshown in Table A4. Reaction temperature, catalyst-to-oil ratio, WHSV andevaluation result were listed in Table A5.

wherein,

conversion=gasoline yield+liquefied gas yield+Dry gas yield+coke yieldcoke selectivity=coke yield*100/conversion

Example A.3.2.1

A catalyst was prepared according to Example A.3.1.1, except that thesame amount of RE(8)Y zeolite was used in place of Zr(8)Y zeolite toproduce a catalyst named as DC1. Then DC1 was evaluated according toExample A.3.1.1. The evaluation result was listed in Table A5.

Example A.3.2.2

A catalyst was prepared according to Example A.3.1.1, except that thesame amount of Zr(W)Y zeolite was used in place of Zr(8)Y zeolite toproduce a catalyst named as DC2. Then DC2 was evaluated according toExample A.3.1.1. The evaluation result was listed in Table A5.

TABLE A4 Feedstock Wuhun III Density (20° C.), g/cm³ 0.9044 Refraction(20° C.) 1.5217 Viscosity (100° C.), mm²/s 9.96 Freezing point, ° C. 40Aniline point, ° C. 95.8 C, wt % 85.98 H, wt % 12.86 S, wt % 0.55 N, wt% 0.18 Residual Carbon, wt % 3.0 Distillation range, ° C. Initialdistillation point  5% 243 10% 294 30% 316 50% 395 70% 429 90% 473 —

TABLE A5 Example A.3.1.1 A.3.2.1 A.3.2.2 Catalyst C1 DC1 DC2 ReactionTemp, ° C. 500 500 500 Catalyst-to-oil weight ratio 5 5 5 WHSV, h⁻¹ 1616 16 Production Distribution, wt % Dry gas 1.15 1.10 1.18 liquefied gas11.15 11.66 12.03 coke 4.02 5.45 4.65 gasoline 56.40 53.08 50.30 diesel20.17 21.46 23.02 Heavy oil 7.11 7.25 8.82 Conversion, wt % 72.72 71.2968.16 Coke selectivity 5.53 7.64 6.82

Example A.3.1.2

According to Example A.1.1.1, the used amount of zirconium nitrate wasadjusted to prepare a Zr-modified Y zeolite, named as Zr(6)Y, whereinthe ratio of the used amount of zirconium nitrate (as ZrO₂) to theweight amount of the zeolite was 6:100 by weight.

323 g of pseudobohemite (having a solid content of 62 wt %) and 1343 gof deionized water were mixed. The mixture was stirred for 15 minutesand mixed homogenously to produce a pseudoboehmite slurry, the pH valueof which was adjusted with diluted hydrochloric acid to 3.5. Theresulting slurry was aged at room temperature for 6 hours. To the agedslurry were added 447 g of kaolin (having a solid content of 76 wt %)and 372 g of alumina sol (having an alumina content of 21.5 wt %). Theresulting slurry was stirred for 60 minutes. To the above slurry wasadded a slurry formed by slurrying 380 g (dry basis) of the abovemodified Zr(6)Y zeolite and 880 g of deionized water. The resultingmixture was stirred for 60 minutes to produce a catalyst slurry, whichwas spray-dried and shaped, and calcined at 550° C. for 1 hour toproduce a catalytic cracking catalyst, named as C11. The ZrO₂ content ofthe catalyst C11, measured by XRF, was 2.2 wt %.

Example A.3.1.3

A Zr-modified Y zeolite was prepared according to Example A.1.1.2, namedas Zr(10)Y, wherein ZrO2:zeolite=10:100.

421 g of kaolin (having a solid content of 76 wt %), 465 g of aluminasol (having an alumina content of 21.5 wt %) and 732 g of deionizedwater were added to and slurried in a slurry vessel, to which was added1667 g of an acidified pseudoboehmite (being acidified with hydrochloricacid, the mole ratio of hydrochloric acid/alumina=0.15, and having asolid content of 12 wt %). After stirring for 60 minutes, to the vesselwas added a slurry formed by slurrying 380 g (dry basis) of the abovemodified Zr(10)Y zeolite and 880 g of deionized water. The resultingmixture was stirred for 60 minutes to produce a catalyst slurry, whichwas spray-dried and shaped, and calcined at 550° C. for 1 hour toproduce a catalytic cracking catalyst, named as C21. The ZrO₂ content ofthe catalyst C21, measured by XRF, was 3.5 wt %.

Example A.3.1.4

447 g of kaolin, 372 g of alumina sol and 800 g of deionized water weremixed and slurried for 60 minutes. After adding 1667 g of an acidifiedpseudobohemite, the resulting slurry was further stirred for 60 minutes.To the resulting mixture was added a slurry formed by slurrying 380 g(dry basis) of the above modified Ti(2)Y zeolite and 880 g of deionizedwater. The resulting mixture was stirred for 60 minutes to produce acatalyst slurry, which was spray-dried and shaped, and calcined at 650°C. for 2 hours to produce a catalytic cracking catalyst, named as C31.The TiO₂ content of the catalyst C31, measured by XRF, was 0.75 wt %.

Example A.3.1.5

447 g of kaolin, 372 g of alumina sol and 800 g of deionized water weremixed and slurried for 60 minutes. After adding 1667 g of an acidifiedpseudobohemite, the resulting slurry was further stirred for 60 minutes.To the resulting mixture was added a slurry formed by slurrying 380 g(dry basis) of the above modified Ti(4)Y zeolite and 880 g of deionizedwater. The resulting mixture was stirred for 60 minutes to produce acatalyst slurry, which was spray-dried and shaped, and calcined at 650°C. for 2 hours to produce a catalytic cracking catalyst, named as 41.The TiO₂ content of the catalyst C41, measured by XRF, was 1.5 wt %.

Example A.3.1.6

A catalyst was prepared according to Example A.3.1.5, except that thesame amount of Ti(4)Y-1 was used in place of the Ti(4)Y zeolite toproduce the catalyst, named as C41-1.

Example A.3.1.7

A catalyst was prepared according to Example A.3.1.5, except that a REYzeolite prepared according to the prior method (SiO₂/Al₂O₃ molarratio=5.1, rare earth content=3.8 wt %, Na2O content=0.4 wt %) was usedin place of a part of the Ti(4)Y zeolite. The weight ratio of the REYzeolite prepared according to the prior method to the Ti(4)Y zeolite was1:1 to produce a catalyst, named as C41-2.

Example A.3.1.8

According to Example A.1.1.4, the used amount of titanium tetrachloridewas adjusted to prepare a Ti-modified Y zeolite, named as Ti(8)Y,wherein the ratio of the used amount of titanium tetrachloride (as TiO₂)to the weight amount of the zeolite was 8:100 by weight.

421 g of kaolin, 698 g of alumina sol and 900 g of deionized water weremixed and slurried for 60 minutes. After adding 1250 g of an acidifiedpseudobohemite, the resulting slurry was further stirred for 60 minutes.

To the resulting mixture was added a slurry formed by slurrying 380 g(dry basis) of the above modified Ti(8)Y zeolite and 800 g of deionizedwater. The resulting mixture was stirred for 60 minutes to produce acatalyst slurry, which was spray-dried and shaped, and calcined at 700°C. for 2 hours to produce a catalytic cracking catalyst, named as C51.The TiO₂ content of the catalyst C51, measured by XRF, was 3.0 wt %.

Example A.3.1.9

The same starting materials as those used in Example A.3.1.2 were used,except for the metal-modified Y zeolite.

355 g of pseudoboehmite and 1478 g of deionized water were mixed andstirred for 30 minutes to produce a pseudoboehmite slurry, the pH ofwhich was adjusted with a suitable amount of diluted hydrochloric acidto 3.8. The resulting slurry was aged at 60° C. for 2 hours. To the agedslurry were added 395 g of kaolin and 465 g of alumina sol. Theresulting mixture was stirred for 60 minutes. Then to the slurry wasadded a slurry formed by slurrying 380 g (dry basis) of the abovemodified Ti—Zr—Y zeolite and 880 g of deionized water. The resultingmixture was stirred for 60 minutes to produce a catalyst slurry, whichwas spray-dried and shaped, and calcined at 600° C. for 3 hours toproduce a catalytic cracking catalyst, named as C61.

Example A.3.2.3

A catalyst was prepared according to Example A.3.1.8, except that thesame amount of RE(8)Y zeolite was used in place of Ti(8) Y zeolite toproduce a catalyst, named as DC11. The RE₂O₃ content of the catalystDC11, measured by XRF, was 2.32 wt %.

Example A.3.2.4

A catalyst was prepared according to Example A.3.1.8, except that thesame amount of Ti(W)Y zeolite was used in place of Ti(8)Y zeolite toproduce a catalyst, named as DC21. The TiO₂ content of the catalystDC21, measured by XRF, was 2.40 wt %.

Example A.3.2.5

A catalyst was prepared according to Example A.3.1.2, except that thesame amount of Zr(W)Y zeolite was used in place of Zr(6)Y zeolite toproduce a catalyst, named as DC31. The ZrO₂ content of the catalystDC31, measured by XRF, was 2.18 wt %.

The catalysts C11-C61 and DC11-DC31 were pretreated at 800° C. in a 100%steam condition for 8 hours. Then the pretreated catalyst was tested ona small-scale fixed fluidised bed (ACE) for catalyst evaluation. Thefeedstock for evaluation was Wuhun III, the properties of which wereshown in Table A4. Reaction temperature, catalyst-to-oil ratio, WHSV andevaluation result were listed in Table A6.

wherein, conversion=gasoline yield+liquefied gas yield+Dry gasyield+coke yield

TABLE A6 Evaluation Result Example A.3.1.2 A.3.1.3 A.3.1.4 A.3.1.5A.3.1.6 A.3.1.7 A.3.1.8 A.3.1.9 A.3.2.3 A.3.2.4 A.3.2.5 Catalysts C11C21 C31 C41 C41-1 C41-2 C51 C61 DC11 DC21 DC31 Zeolites Zr(6)Y Zr(10)YTi(2)Y Ti(4)Y Ti(4)Y-1 Ti(4)YREY Ti(8)Y Ti—Zr—Y RE(8)Y Ti(W)Y Zr(W)YReaction 500 500 500 500 500 500 500 500 500 500 500 Temp, ° C.Catalyst- 8.04 8.04 8.04 8.04 8.04 8.04 8.04 8.04 8.04 8.04 8.04 to-oilweight ratio WHSV, h⁻¹ 16 16 16 16 16 16 16 16 16 16 16 ProductionDistribution, wt % Dry gas 1.35 1.32 1.33 1.34 1.33 1.3 1.32 1.35 1.341.34 1.35 liquefied gas 14.04 13.61 13.30 14.43 14.21 13.96 14.52 14.2613.58 13.35 13.72 coke 6.71 6.86 7.52 7.05 7.13 7.42 6.76 6.71 8.02 7.297.12 gasoline 54.11 53.52 52.98 53.44 53.25 53.51 53.24 53.87 52.2249.87 50.55 diesel 16.76 16.84 16.96 16.65 16.94 16.71 16.94 16.84 16.8917.19 17.37 Heavy oil 7.03 7.85 7.91 7.09 7.14 7.1 7.22 6.97 7.95 10.969.89 Total 100 100 100 100 100 100 100 100 100 100 100 Conversion, 76.2175.31 75.13 76.26 75.92 76.19 75.84 76.19 75.16 71.85 72.74 wt % coke/0.08805 0.09109 0.10009 0.09245 0.09391 0.09739 0.08914 0.08807 0.106710.10146 0.09788 conversion

B.1 Zeolite Modification Example B.1.1.1

(1) At room temperature, 200 g of NaY zeolite (dry basis, 75 wt %) and1500 ml of a hydrochloric acid solution having a molar concentration of0.5 mol/L were mixed and stirred for 30 minutes. After filtering, thefilter cake was washed with 1500 ml deionized water to produce anacid-treated NaY zeolite, which had a Na2O content of 3.5 wt %;

(2) The acid-treated NaY zeolite was calcined at 300° C. for 3 hours toproduce a zeolite having a solid content of 96 wt %, named as F1;

(3) 5.23 g of zirconium nitrate Zr(NO₃)₄.5H₂O was dissolved in 200 g ofethanol (analytically pure, ethanol content=99.9 wt %) to produce animpregnation liquor. The impregnation liquor and the treated Y zeoliteF1 were mixed homogenously and kept by standing at room temperature for1 hour.

(4) The product from the step (3) and 800 ml of ethanol were mixed andtransferred to an autoclave, to which nitrogen was introduced. Thepressure was kept at 0.5 MPa. Then the mixture was kept by standing atroom temperature for 12 hours. After filtering, the filter cake washeat-dried at 100° C. for 24 hours.

(5) The product from the step (4) was calcined in a nitrogen atmosphereat 500° C. for 4 hours to produce a Zr-modified Y zeolite, named asZrY(1), the properties of which were shown in Table B2.

Example B.1.1.2 to Example B.1.1.7

With reference to Example B.1.1.1, modified zeolites were preparedaccording to the process of the present invention. The operationconditions and the product properties were shown in Table B2.

Example B.1.1.8

A modified zeolite was prepared according to Example B.1.1.1, exceptthat in the step (4), nitrogen was introduced and the pressure (gaugepressure) was kept at 0 MPa. The obtained modified zeolite was named asZrY(1)-1, the properties of which were shown in Table B2.

Example B.1.1.9

A modified zeolite was prepared according to Example B.1.1.1, exceptthat in the step (1):

(1) At room temperature, 200 g of NaY zeolite (dry basis, 75 wt %) and1500 ml of a EDTA solution having a molar concentration of 0.5 mol/Lwere mixed and stirred for 30 minutes. After filtering, the filter cakewas washed with 1500 ml deionized water to produce an acid-treated NaYzeolite, which had a Na2O content of 3.5 wt %;

Steps (2)-(5) were identical to those in Example B.1.1.1. The obtainedmodified zeolite was named as ZrY(1)-2, the properties of which wereshown in Table B2.

Example B.1.2.1

200 g of NaY zeolite (the same as that in Example B.1.1.1) and 2000 g ofdeionized water were slurried. To the slurry was added 60 g of ammoniumsulfate. The resulting slurry was adjusted with diluted hydrochloricacid to pH=4.0, warmed upto to 80° C. and exchanged for 1 hour. Afterfiltering and washing with water, the filter cake was calcined at 550°C. in a 100% steam atmosphere for 2 hours. The above procedure wasrepeated twice to produce a modified Y zeolite.

Then, the resulting Y zeolite and 2000 g of deionized water wereslurried. To the slurry was added 45 ml of a RECl₃ solution (270 g/l).The resulting slurry was adjusted with diluted hydrochloric acid topH=3.8, warmed upto to 80° C. and exchanged for 1 hour. To the mixturewas added 45 g of ammonium sulfate, and the resulting mixture wasstirred for 1 hour. After filtering and washing, the filter cake wascalcined at 550° C. in a 100% steam atmosphere for 2 hours. Finally, arare earth modified REY zeolite was obtained and named as REY, theproperties of which were shown in Table B3.

Example B.1.2.2

The modified zeolite was prepared according to B.1.1.2, except that thesame amount of zirconium oxychloride ZrOCl₂.8H₂O was dissolved in 200 gof deionized water. Finally, a Zr-modified zeolite was obtained andnamed as Zr(W)Y, the properties of which were shown in Table B3.

Example B.1.2.3

200 g of NaY zeolite and 2000 g of deionized water were slurried. To theresulting slurry was added 60 g NH4Cl. The slurry was adjusted to a pHof 3.8, warmed upto 80° C., and exchanged for 2 hours. After filteringand washing with water, the filter cake was calcined at 600° C. in a100% steam condition for 2 hours.

The calcined zeolite and 2000 g of deionized water were slurried. To theresulting slurry was added 45 g NH4Cl and 31.4 g zirconium oxychlorideZrOCl₂.8H₂O to conduct a second ion-exchange substantially at the sametemperature and for the same time as the first exchange. After filteringand washing with water, the filter cake was calcined at 600° C. in a100% steam condition for 2 hours. Finally, a Zr-modified zeolite wasobtained and named as Zr(J)Y, the properties of which were shown inTable B3.

Example B.1.2.4

A Zr-modified Y zeolite was prepared according to Example 1 ofCN101134576A. Finally, the Zr-modified zeolite was obtained and named asZr(G)Y, the properties of which were shown in Table B3.

Example B.1.2.5

200 g of DASY0.0 zeolite was added to 500 g of absolute ethanol under aviolent stirring to form a suspension, to which was added 50 g/L of asolution of butyl titanate-absolute ethanol (as TiO₂) under a violentstirring. The mixture was air-dried overnight under stirring. Theresulting sample was calcined at 500° C. for 5 hours to produceTi-modified zeolites with titanium content of 7.9 wt %, named as Ti(D)Y.

It could be seen from the FT-IR spectra of modified Y zeolites in FIG. 1that the antisymmetric stretching vibration frequency (1050-1150 cm⁻¹)and the symmetric stretching vibration frequency (750-820 cm⁻¹) of theZr(G)Y zeolite provided in the prior art (e.g. Example B.1.2.4) had ared-shift in a direction toward the lower frequency, showing that Zrentered the framework structure of the Y zeolite. The modified Yzeolites provided by the present invention (e.g. ZrY and TiY) did notshow the red shift, showing that Zr and Ti did not enter the frameworkstructure of the zeolite.

It could be seen from the ²⁷Al-NMR spectra of modified Y zeolites inFIG. 2 that the modified Y zeolite had much tetrahedral-coordinatedframework aluminum (chemical shift 60) and little hexahedral-coordinatedframework aluminum (chemical shift 0). Compared to the Y zeolite, thepeak of tetrahedral-coordinated framework aluminum of the ZrY zeoliteprepared by organic solution impregnation method became wider and movedtowards the lower chemical shift, showing that Zr entering the interiorof the zeolite interacted with the zeolite framework [AlO4]. Thisinteraction caused the spectrum peak of tetrahedral-coordinatedframework aluminum moves to higher field, meanwhile the spectrum peak ofthe distorted tetrahedral-coordinated framework aluminum was remarkable(chemical shift 40). The ratio of the distorted tetrahedral-coordinatedframework aluminum to the tetrahedral-coordinated framework aluminumcould be e.g. 0.1-0.6. Zr(W)Y and Ti(D)Y zeolites, prepared according toExample B.1.2.2 (aqueous solution impregnation) and Example B.1.2.5, hadno remarkable change in the peak of distorted tetrahedral-coordinatedframework aluminum, showing that Zr or Ti had little interaction withthe zeolite's framework [AlO4], and the ratio of the distortedtetrahedral-coordinated framework aluminum to thetetrahedral-coordinated framework aluminum was less than 0.1. It couldbe seen that the modification method according to the present inventionwas more favorable for the metal ions to enter the interior of thezeolite, interact with the zeolite's framework [AlO4], and have aneffect of stabilizing the zeolite framework structure.

TABLE B1 Once-exchanged- Raw Material NaY DASY(0.0) once-calcinedElemental composition, wt % Na₂O 12.8 1.2 3.7 Al₂O₃ 21.9 23.6 23.4 SiO₂64.4 71.7 72.0 Unit cell size, nm 2.466 2.448 2.453 crystallinity, %81.6 65.6 78.0 Total specific surface area, 762 620 644 m²/g Total porevolume, ml/g 0.377 0.353 0.352

TABLE B2 Example B.1.1.1 B.1.1.2 B.1.1.3 B.1.1.4 B.1.1.5 Step Y zeoliteraw NaY DASY(0.0) Once-exchanged- Once-exchanged- NaY (1) materialonce-calcined once-calcined Acid solution 0.5 0.1 1.0 0.2 0.5concentration, mol/L Acid Hydrochloric hydrochloric Oxalic SulfuricHydrochloric acid acid acid acid acid Acid 10 10 10 10 10solution:zeolite weight ratio The content of 3.5 0.6 1.2 0.8 3.5 Na₂Oafter treatment, wt % Step Calcination 300 300 350 350 300 (2)Temperature, ° C. Calcination time, 3 3 3 3 3 hours Water content, wt %4 3 1.5 1.5 4 Step Compound zirconium zirconium zirconium zirconiumtitanium (3) containing IVB nitrate oxychloride isopropoxideisopropoxide tetrachloride group metal Solvent ethanol ethanol n-hexanen-hexane butanone Water content in 0.1 0.1 0.2 0.2 0.3 solvent, wt %Solvent:Zeolite 1.3 1.5 1.5 1.2 1.3 weight ratio Metal salt (as 0.010.03 0.06 0.10 0.02 oxide):zeolite weight ratio Step Used solventethanol ethanol n-hexane n-hexane butanone (4) Solvent:Zeolite 5.1 10.010.0 10.0 5.1 weight ratio Introduced Inert nitrogen nitrogen nitrogennitrogen nitrogen Gas Pressure, MPa 0.5 1.0 0.5 0.8 0.5 Temperature, °C. 26 25 60 25 25 Time, hour 12 8 5 8 5 Manner By Being Being Bystanding being standing stirred stirred stirred Step Drying 100 120 120120 100 (4) Temperature, ° C. Drying Time, hour 24 6 6 6 12 Step InertGas nitrogen nitrogen nitrogen nitrogen nitrogen (5) Calcination 500 550550 550 500 Temperature, ° C. Calcination Time, 4 2 3 3 3 hourMetal-modified Y zeolite, ZrY(1) ZrY(3) ZrY(6) ZrY(10) TiY(2) No. Na₂O,wt % 1.0 0.5 0.8 0.6 1.2 Al₂O₃, wt % 23.3 23.5 22.2 20.5 22.8 SiO₂, wt %73.8 72.8 70.5 67.8 73.1 ZrO₂, wt % 0.9 2.8 6.1 10.5 TiO₂, wt % 2.2 α0,nm 2.456 2.448 2.450 2.452 2.451 Crystallinity, % 78.8 64.7 70.6 72.276.9 Specific surface area, m²/g 710 616 624 635 702 lattice collapse1048 1050 1045 1047 1044 temperature, ° C. The ratio of the distorted0.2 0.3 0.5 0.6 0.2 tetrahedral-coordinated framework aluminum to thetetrahedral-coordinated framework aluminum The percent of the 32.5 42.848.7 50.3 38.6 secondary pores (pore diameter of 6-20 nm) to the totalsecondary pores (pore diameter of 2-100 nm) Example B.1.1.6 B.1.1.7B.1.1.8 B.1.1.9) Step Y zeolite raw material Once-exchangedOnce-exchanged- NaY NaY (1) once-calcined once-calcined Acid solutionconcentration, 1.0 1.0 0.5 0.5 mol/L Acid acetic acid oxalic acidhydrochloric EDTA acid Acid solution:zeolite weight 10 10 10 10 ratioThe content of Na₂O after 1.0 1.0 3.5 3.5 treatment, wt % StepCalcination Temperature, ° C. 350 350 300 300 (2) Calcination time,hours 3 3 3 3 Water content, wt % 1.8 1.5 4 4 Step Compound containingIVB butyl titanate butyl zirconium zirconium (3) group metal titanate +zirconium nitrate nitrate nitrate Solvent cyclohexane ethanol ethanolethanol Water content in solvent, wt % 0.2 0.1 0.1 0.1 Solvent:Zeoliteweight ratio 1.5 1.5 1.3 1.3 Metal salt (as oxide):zeolite 0.10 0.080.01 0.01 weight ratio Step Used solvent cyclohexane Ethanol ethanolethanol (4) Solvent:Zeolite weight ratio 10.0 8.0 5.1 5.1 IntroducedInert Gas nitrogen nitrogen nitrogen nitrogen Pressure, MPa 0.5 1.5 0.00.5 Temperature, ° C. 25 80 26 26 Time, hour 10 24 12 12 Manner Beingstirred Being stirred By By standing standing Step Drying Temperature, °C. 120 120 100 100 (4) Drying Time, hour 6 24 24 24 Step Inert Gasnitrogen nitrogen nitrogen nitrogen (5) Calcination Temperature, ° C.550 550 500 500 Calcination Time, hour 2 3 4 4 Metal-modified Y zeolite,No. TiY(10) Ti—Zr—Y ZrY(1)-1 ZrY(1)-2 Na₂O, wt % 1.0 0.8 1.0 0.9 Al₂O₃,wt % 21.5 21.9 23.2 23.4 SiO₂, wt % 67.1 69.0 73.9 73.6 ZrO₂, wt % 3.80.9 0.9 TiO₂, wt % 9.8 4.0 α0, nm 2.455 2.455 2.454 2.455 crystallinity,% 73.5 72.9 71.5 77.7 specific surface area, m²/g 642 639 700 699lattice collapse temperature, ° C. 1045 1050 1045 1048 the ratio of thedistorted 0.5 0.5 0.2 0.2 tetrahedral-coordinated framework aluminum tothe tetrahedral-coordinated framework aluminum The percent of thesecondary 49.8 44.4 35.4 33.9 pores (pore diameter of 6-20 nm) to thetotal secondary pores (pore diameter of 2-100 nm)

TABLE B3 Example B.1.2.1 B.1.2.2 B.1.2.3 B.1.2.4 B.1.2.5 Y zeolite No.REY Zr(W)Y Zr(J)Y Zr(G)Y Ti(D)Y Na₂O, wt % 1.2 0.8 0.6 0.5 1 Al₂O₃, wt %21.4 20.6 21.8 20.8 21.5 SiO₂, wt % 70.5 70.2 71 70.7 69.3 ZrO₂, wt % 86.2 7.5 TiO₂, wt % 7.9 RE₂O₃, wt % 6.6 α0, nm 2.451 2.45 2.452 2.4512.453 crystallinity, % 62.7 51.9 55.7 60.2 59.6 specific surface area,m²/g 640 536 548 624 610 lattice collapse temperature, ° C. 1043 10271028 1041 1033 the ratio of the distorted 0.05 0.01 0.02 0.01tetrahedral-coordinated framework aluminum to thetetrahedral-coordinated framework aluminum

B.2 Stability of the Modified Zeolite

Modified Y zeolites prepared according to Example B.2.1.1-B.2.1.9 andB.2.2.1-B.2.2.5 were aged at 800° C. under a 100% steam condition for 8hours and 17 hours respectively to determine the crystallinity and thespecific surface area, and the crystallinity retention and the specificsurface area retention were calculated. The aged zeolites were subjectedto the light oil micro-activity (MA) test. The results were listed inTable B4.

TABLE B4 Example B.2.1.X 1 2 3 4 5 6 7 8 9 Y zeolite ZrY(1) ZrY(3)ZrY(6) ZrY(10) TiY(2) TiY(10) Ti—Zr—Y ZrY(1)-1 ZrY(1)-2 800° C./8 h 61.262.8 63.7 68.4 63.1 67.5 68.6 62.0 61.8 crystallinity retention, % 800°C./17 h 55.5 57.0 56.7 62.5 57.6 60.1 60 56.5 56.1 crystallinityretention, % 800° C./8 h specific 62.0 61.3 62.9 69.6 66.1 68 69.6 62.861.0 surface area retention, % 800° C./17 h 57.2 56.7 57.6 63.9 59.662.2 62.8 57.0 56.4 specific surface area retention, % 800° C./8 h 80 8284 87 85 86 87 80 80 activity, % 800° C./17 h 76 77 79 82 79 80 81 75 77activity, % Example B.2.2.X 1 2 3 4 5 Y zeolite REY Zr(W)Y Zr(J)Y Zr(G)YTi(D)Y 800° C./8 h crystallinity 63.2 50.4 50.5 60.8 61.6 retention, %800° C./17 h crystallinity 56.5 45.8 42.5 52.9 53 retention, % 800° C./8h specific surface 67.1 58 54.2 64.9 62.4 area retention, % 800° C./17 hspecific surface 61.2 52.6 49.8 58.2 59.1 area retention, % 800° C./8 hactivity, % 85 75 72 80 72 800° C./17 h activity, % 79 68 65 75 66

B.3 Catalyst Example B.3.1.1

The modified Y zeolite prepared according to the present invention,Zr(6)Y, was used as active component to prepare the catalyst accordingto the conventional preparation method of the catalytic crackingcatalyst. The preparation was as follows.

According to the ratio of zeolite (dry basis):kaolin (drybasis):pseudobohemite (as Al₂O₃):alumina sol (as Al₂O₃) being38:34:20:8, kaolin and decationized water were mixed and slurried. Tothe resulting slurry was added alumina sol, and further addedpseudoboehmite under a continuous stirring. After 30 minutes ofstirring, a liquor containing zeolite was added to the colloid. Theresulting mixture was mixed homogenously, spray-dried and shaped toproduce a catalyst, named as C1.

Evaluation of Heavy Oil Cracking Performance:

The catalyst was pretreated at 800° C. in a 100% steam condition for 8hours. Then the pretreated catalyst was tested on a small-scale fixedfluidised bed (ACE) for catalyst evaluation. The feedstock forevaluation was a mixed oil of ZhengHai VGO and DaQing atmosphericresidue (80:20 by weight), the properties of which were shown in TableB5. Reaction Temp=500° C., WHSV=16 h⁻¹, Catalyst-to-oil weight ratio=45.The evaluation result was listed in Table B6.

wherein,

conversion=gasoline yield+liquefied gasyield+Dry gasyield+coke yield

coke selectivity=coke yield×100/conversion

TABLE B5 DaQing Feedstock ZhengHai VGO Atmospheric Residue Density (20°C.), g/cm³ 0.9154 0.8906 Refraction (70° C.) 1.4926 1.4957 (20° C.)Viscosity (100° C.) mm²/s 6.962 24.84 SARA composition, % Saturatedhydrocarbons 64.0 51.2 Aromatic hydrocarbons 32.0 29.7 Resin 4.0 18.3Asphaltene 0.0 0.8 Freezing point, ° C. 35 43 Aniline point, ° C.82.0 >105 C, wt % 85.38 86.54 H, wt % 12.03 13.03 S, wt % 2.0 0.13 N, wt% 0.16 0.3 Residual Carbon % 0.18 4.3 Distillation range, ° C. Initialdistillation point 329 282  5% 363 351 10% 378 370 30% 410 482 50% 436553 70% 462 — 90% 501 —

Example B.3.1.2

A catalyst was prepared according to Example B.3.1.1, except that thesame amount of TiY(2) zeolite was used in place of ZrY(6) zeolite toproduce a catalyst C2. Then the evaluation of C2 was done according toExample B.3.1.1. The evaluation result was listed in Table B6.

Example B.3.2.1 to Example B.3.2.3

A series of catalysts were prepared according to Example B.3.1.1, exceptthat the same amount of REY zeolite, the same amount of Zr(W)Y zeolite,and the same amount of Ti(D)Y zeolite were respectively used in place ofZrY(6) zeolite to produce the catalysts DC1, DC2 and DC3. Then theevaluation of DC1-DC3 was done according to Example B.3.1.1. Theevaluation result was listed in Table B6.

TABLE B6 Example B.3.1.1 B.3.1.2 B.3.2.1 B.3.2.2 B.3.2.3 Zeolite No.ZrY(6) TiY(2) REY Zr(W)Y Ti(D)Y Catalyst C1 C2 DC1 DC2 DC3 ReactionTemp, ° C. 500 500 500 500 500 Catalyst-to-oil weight 5 5 5 5 5 ratioWHSV, h⁻¹ 16 16 16 16 16 Production Distribution, wt % Dry gas 1.40 1.391.38 1.39 1.37 liquefied gas 17.15 16.92 16.53 16.44 16.98 coke 4.524.75 5.35 5.16 5.33 gasoline 50.80 49.98 49.70 45.62 48.29 diesel 17.8518.76 18.64 19.97 18.73 Heavy oil 8.28 8.20 8.40 11.42 9.30 Conversion,wt % 73.87 73.04 72.96 68.61 71.97 Total liquid yield, wt % 85.80 85.6684.87 82.03 84.00 Coke selectivity 6.12 6.50 7.33 7.52 7.41

Example B.3.1.3

A Zr-modified Y zeolite was prepared according to Example B.1.1.1, namedas Zr(2)Y, wherein the weight ratio of zirconium nitrate(as ZrO₂):Yzeolite=0.02:1.

323 g of pseudoboehmite and 1343 g of deionized water were mixed andstirred for 15 minutes to produce a pseudoboehmite slurry. The slurrywas adjusted with diluted hydrochloric acid (having a concentration of15 wt %) to a pH of 3.5, and aged at room temperature for 6 hours. Tothe aged slurry were added 421 g of kaolin and 465 g of alumina sol.After stirring for 60 minutes, to the resulting slurry was added aslurry formed by slurrying 380 g (dry basis) of the above modifiedZrY(2) zeolite and 800 g of deionized water. The resulting mixture wasstirred for 60 minutes to produce a catalyst slurry, which wasspray-dried and shaped, and calcined at 550° C. for 2 hours to produce acatalytic cracking catalyst, named as C17. The ZrO₂ content of thecatalyst C17, measured by XRF, was 0.75 wt %.

Example B.3.1.4

421 g of kaolin, 465 g of alumina sol and 732 g of deionized water wereadded to and slurried in a slurry vessel, to which was added 1667 g ofan acidified pseudoboehmite. After stirring for 60 minutes, to thevessel was added a slurry formed by slurrying 380 g (dry basis) of theabove modified Zr(6)Y zeolite and 800 g of deionized water. Theresulting mixture was stirred for 60 minutes to produce a catalystslurry, which was spray-dried and shaped, and calcined at 550° C. for 1hour to produce a catalytic cracking catalyst, named as C18. The ZrO₂content of the catalyst C18, measured by XRF, was 2.18 wt %.

Example B.3.1.5

421 g of kaolin, 558 g of alumina sol and 800 g of deionized water weremixed and slurried for 60 minutes. After adding 1500 g of an acidifiedpseudobohemite, the resulting slurry was further stirred for 60 minutes.To the resulting mixture was added a slurry formed by slurrying 380 g(dry basis) of the above modified ZrY(10) zeolite and 800 g of deionizedwater. The resulting mixture was stirred for 60 minutes to produce acatalyst slurry, which was spray-dried and shaped, and calcined at 650°C. for 2 hours to produce a catalytic cracking catalyst, named as C19.The ZrO₂ content of the catalyst C19, measured by XRF, was 3.52 wt %.

Example B.3.1.6

According to Example B.2.1.5, a Ti-modified Y zeolite was prepared andnamed as TiY(8), wherein during the impregnation of the step (3), theweight ratio of titanium tetrachloride (as TiO₂) to zeolite was 0.08:1.

421 g of kaolin and 380 g of deionized water were mixed and slurried for60 minutes. After adding 1667 g of an acidified pseudobohemite, theresulting slurry was further stirred for 30 minutes. To the resultingmixture was added a slurry formed by slurrying 380 g (dry basis) of theabove modified TiY(8) zeolite and 800 g of deionized water. Afterstirring for 60 minutes, to the resulting slurry was added 465 g ofalumina sol. The resulting mixture was stirred for 30 minutes to producea catalyst slurry, which was spray-dried and shaped, and calcined at700° C. for 2 hours to produce a catalytic cracking catalyst, named asC20. The TiO₂ content of the catalyst C20, measured by XRF, was 3.02 wt%.

Example B.3.1.7

According to Example B.2.1.5, a Ti-modified Y zeolite was prepared andnamed as TiY(4), wherein during the impregnation of the step (3), theweight ratio of titanium tetrachloride (as TiO₂) to zeolite was 0.04:1.

323 g of pseudoboehmite and 1478 g of deionized water were mixed. Themixture was stirred for 30 minutes to produce a pseudoboehmite slurry,the pH value of which was adjusted with a suitable amount of dilutedhydrochloric acid to 3.8. The resulting slurry was aged at 60° C. for 2hours. To the aged slurry were added 421 g of kaolin and 465 g ofalumina sol. The resulting slurry was stirred for 60 minutes. To theabove slurry was added a slurry formed by slurrying 380 g (dry basis) ofthe above modified TiY(4) zeolite and 800 g of deionized water. Theresulting mixture was stirred for 60 minutes to produce a catalystslurry, which was spray-dried and shaped, and calcined at 600° C. for 3hours to produce a catalytic cracking catalyst, named as C21. The TiO₂content of the catalyst C21, measured by XRF, was 1.48 wt %.

Example B.3.1.8

According to Example B.2.1.5, a Hf-modified Y zeolite was prepared andnamed as HfY(6), wherein during the impregnation of the step (3), theweight ratio of hafnium nitrate (as HfO₂) to zeolite was 0.06:1.

421 g of kaolin and 380 g of deionized water were mixed and slurried for60 minutes. After adding 1667 g of an acidified pseudobohemite, theresulting slurry was further stirred for 30 minutes. To the resultingmixture was added a slurry formed by slurrying 380 g (dry basis) of theabove modified HfY(6) zeolite and 800 g of deionized water. Afterstirring for 60 minutes, to the resulting slurry was added 465 g ofalumina sol. The resulting mixture was stirred for 30 minutes to producea catalyst slurry, which was spray-dried and shaped, and calcined at700° C. for 2 hours to produce a catalytic cracking catalyst, named asC22. The HfO₂ content of the catalyst C22, measured by XRF, was 2.11 wt%.

Example B.3.1.9

421 g of kaolin and 380 g of deionized water were mixed and slurried for60 minutes. After adding 1667 g of an acidified pseudobohemite, theresulting slurry was further stirred for 30 minutes. To the resultingmixture was added a slurry formed by slurrying 380 g (dry basis) of theabove modified Ti—Zr—Y zeolite and 800 g of deionized water. Afterstirring for 60 minutes, to the resulting slurry was added 465 g ofalumina sol. The resulting mixture was stirred for 30 minutes to producea catalyst slurry, which was spray-dried and shaped, and calcined at700° C. for 2 hours to produce a catalytic cracking catalyst, named asC23. The TiO₂ and ZrO₂ contents of the catalyst C23, measured by XRF,were 1.50 wt % and 1.48 wt % respectively.

Example B.3.1.10 to Example B.3.1.12

A series of catalysts were prepared according to Example B.3.1.3, exceptthat the same amount of ZrY(1), the same amount of ZrY(1)-1 and the sameamount of ZrY(1)-2 were respectively used in place of ZrY(2) zeolite toproduce the catalysts C24, C25 and C26.

Example B.3.2.4

A catalyst was prepared according to Example B.3.1.4, except that thesame amount of Zr(W)Y zeolite was used in place of ZrY(6) zeolite toproduce the catalyst DC14. The ZrO₂ content of the catalyst DC14,measured by XRF, was 2.19 wt %.

Example B.3.2.5

500 g of NaY zeolite (dry basis) and 6000 g of deionized water weremixed and slurried. To the resulting slurry was added 200 g of NH₄Cl.The mixture was adjusted to pH=3.8, warmed upto 80° C. to exchange for 2hours, filtered and washed with water. The above procedure was repeatedfor three times. The resulting filter cake was calcined at 600° C. undera 100% steam atmosphere for 2 hours. Then, the calcined Y zeolite and6000 g of deionized water were mixed and slurried. To the slurry wasadded 150 g NH4Cl and 95.1 g of titanium tetrachloride. The mixture waswarmed upto 80° C. to exchange for 3 hours. After filtering and washing,the resulting filter cake was calcined at 600° C., under a 100% steamatmosphere for 2 hours. Finally, a zeolite was obtained and named asTi(J)Y zeolite.

A catalyst was prepared according to Example B.3.1.6, except that thesame amount of Ti(J)Y zeolite was used in place of TiY(8) zeolite toproduce the catalyst DC15. The TiO₂ content of the catalyst DC15,measured by XRF, was 1.72 wt %.

Example B.3.2.6

200 g of NaY zeolite and 2000 g of deionized water were mixed andslurried. To the resulting slurry was added 45 mL of a solution of 270g/l RECl₃. The mixture was adjusted with a diluted hydrochloric acid topH=3.8, and warmed upto 80° C. to exchange for 1 hour. After filteringand washing, the resulting filter cake was calcined at 500° C. for 3hours. Then, the resulting Y zeolite and 2000 g of deionized water weremixed and slurried. To the slurry was added 45 g of ammonium sulfate.The mixture was adjusted with a diluted hydrochloric acid to pH=4.0, andwarmed upto 80° C. to exchange for 1 hour. After filtering and washing,the resulting filter cake was calcined at 600° C., under a 100% steamatmosphere for 3 hours. Finally, a RE-modified zeolite was obtained andnamed as REY(8).

According to the ratio of zeolite (dry basis):kaolin (drybasis):pseudobohemite (as Al₂O₃):alumina sol (as Al₂O₃) being38:34:20:8, kaolin and decationized water were mixed and slurried. Tothe resulting slurry was added alumina sol, and further addedpseudoboehmite under a continuous stirring. After about 30 minutes ofstirring, a liquor containing zeolite was added to the colloid. Theresulting mixture was mixed homogenously, spray-dried and shaped toproduce a catalyst, named as DC16.

The catalysts C17-C26 and DC14-DC16 were pretreated at 800° C. in a 100%steam condition for 17 hours. Then the pretreated catalysts were testedon a small-scale fixed fluidised bed (ACE) for catalyst evaluation. Thefeedstock for evaluation was Wuhun III, the properties of which wereshown in Table B7. Reaction temperature=500° C., and the catalyst-to-oilweight ratio=5. The evaluation result was listed in Table B8.

wherein,

conversion=gasoline yield+liquefied gas yield+Dry gas yield+coke yield

coke selectivity=coke yield/conversion

TABLE B7 Feedstock's properties Feedstock Wuhun III density (20° C.),g/cm³ 0.9044 Refraction (20° C.) 1.5217 Viscosity (100° C.), mm²/s 9.96Freezing point, ° C. 40 Aniline point, ° C. 95.8 C, wt % 85.98 H, wt %12.86 S, wt % 0.55 N, wt % 0.18 Residual Carbon, wt % 3.0 Distillationrange, ° C. Initial distillation point 243  5% 294 10% 316 30% 395 50%429 70% 473 90% —

TABLE B8 Evaluation Result Example B.3.1.3 B.3.1.4 B.3.1.5 B.3.1.6B.3.1.7 B.3.1.8 B.3.1.9 Catalyst No. C17 C18 C19 C20 C21 C22 C23Modified Y Zeolite No. ZrY(2) ZrY(6) ZrY(10) TiY(8) TiY(4) HfY(6)Ti—Zr—Y Reaction Temp, ° C. 500 500 500 500 500 500 500 Catalyst-To-OilRatio 5 5 5 5 5 5 5 (Weight) WHSV, h⁻¹ 16 16 16 16 16 16 16 ProductionDistribution, wt % Dry Gas 1.25 1.12 1.29 1.22 1.10 1.18 1.20 LiquefiedGas 12.04 13.05 11.53 12.09 12.41 12.48 12.35 Coke 5.09 4.26 4.95 4.965.01 4.85 4.99 Gasoline 53.99 54.61 54.59 54.44 54.07 53.95 54.11 Diesel21.41 20.98 21.58 21.34 21.84 21.69 21.36 Heavy Oil 6.22 5.98 6.06 5.955.57 5.85 5.99 Total 100 100 100 100 100 100 100 Conversion, wt % 72.3773.04 72.36 72.71 72.59 72.46 72.65 Coke/Conversion 0.07033 0.058320.06841 0.06822 0.06902 0.06693 0.06869 Example B.3.1.10 B.3.1.11B.3.1.12 B.3.2.4 B.3.2.5 B.3.2.6 Catalyst No. C24 C25 C26 DC14 DC15 DC16Modified Y Zeolite No. ZrY(1) ZrY(1)-1 ZrY(1)-2 Zr(W)Y Ti(J)Y RE(8)YReaction Temp, ° C. 500 500 500 500 500 500 Catalyst-To-Oil Ratio(Weight) 5 5 5 5 5 5 WHSV, h⁻¹ 16 16 16 16 16 16 ProductionDistribution, wt % Dry Gas 1.21 1.22 1.23 1.32 1.18 1.10 Liquefied Gas11.81 11.79 11.89 11.78 12.03 11.66 Coke 4.62 4.52 4.71 5.88 5.25 5.45Gasoline 54.15 54.21 54.48 50.57 50.30 53.08 Diesel 21.88 21.91 21.2822.01 22.12 21.46 Heavy Oil 6.33 6.35 6.41 8.44 9.12 7.25 Total 100 100100 100 100 100 Conversion, wt % 71.79 71.74 72.31 69.55 68.76 71.29Coke/Conversion 0.06435 0.06301 0.06514 0.08454 0.07635 0.0764

We claim:
 1. A metal modified Y zeolite, which contains 1-15 wt % of IVBgroup metal as oxide, wherein the ratio of the zeolite surface's IVBgroup metal content to the zeolite interior's IVB group metal content isnot higher than 0.2.
 2. The metal modified Y zeolite of claim 1, whereinthe ratio of the distorted tetrahedral-coordinated framework aluminum tothe tetrahedral-coordinated framework aluminum in the zeolite latticestructure is 0.2-0.8.
 3. The metal modified Y zeolite of claim 1, whichhas a specific surface area of 600-850 m²/g or 600-750 m²/g, a unit cellsize a0 of 2.448-2.458 nm or 2.450-2.455 nm, a SiO₂/Al₂O₃ molar ratio of5-50, the percent of the secondary pores (pore diameter of 6-20 nm) tothe total secondary pores (pore diameter of 2-100 nm) being 30-50% or50%-65%, and a crystallinity of not less than 60%.
 4. The metal modifiedY zeolite of claim 1, which has an anhydrous chemical compositionformula, as oxide and by weight, of(0-2)Na₂O.(1-15)MO₂.(10-25)Al₂O₃.(65-75)SiO₂ or(0.1-1.2)Na₂O.(1-10)MO₂.(20-24)Al₂O₃.(67-74)SiO₂, wherein M is a IVBgroup metal, selected from one or more of Ti, Zr, Hf and Rf.
 5. Themetal modified Y zeolite of claim 1, wherein the IVB group metal is Tiand/or Zr, and the metal-modified Y zeolite is free of both framework Tiand framework Zr.
 6. The metal modified Y zeolite of claim 1, whereinthe content of the IVB group metal as oxide is 1-10 wt %.
 7. The metalmodified Y zeolite of claim 1, wherein the modifying metal is Ti and/orZr, wherein relative to the non-modified Y zeolite, the antisymmetricstretching vibration frequency (1050-1150 cm⁻¹) and the symmetricstretching vibration frequency (750-820 cm⁻¹) in the infrared spectrumof the metal-modified Y zeolite do not red-shift in a direction towardthe lower frequency.
 8. The metal modified Y zeolite of claim 1, whereinthe IVB group metal comprises Ti and/or Zr.
 9. A process for preparing ametal modified Y zeolite, comprising the steps of: (1) a Y-zeolite rawmaterial is subjected to dewatering so that the raw material has a watercontent by weight of not higher than 5%; (2) the dewatered Y zeoliteobtained from step (1) is contacted with a mixture of a compoundcontaining IVB group metal and an organic solvent, and the resultingmixture is optionally filtered and/or dried; (3) the Y zeolite obtainedfrom step (2) is calcined at 300-700° C.; (4) the Y zeolite obtainedfrom step (3) is contacted with an aqueous acid solution, and thencalcined at 400-800° C. to produce the metal-modified Y zeolitecontaining the IVB group metal; the acid concentration, as H+, is0.1-2.0 mol/L.
 10. The process of claim 9, wherein in the step (2), themixing weight ratio of the compound containing IVB group metal, the Yzeolite and the organic solvent is 0.01-0.15:1:1-50, wherein the weightof the compound containing IVB group metal is calculated as oxide, andthe Y zeolite is calculated in a dry basis.
 11. The process of claim 9,wherein in the step (2), the weight ratio of the compound containing IVBgroup metal (as oxide):the Y zeolite (dry basis):the organic solvent is0.01-0.1:1:5-30.
 12. The process of claim 9, wherein in the step (2),the procedure of contacting the dewatered Y zeolite obtained from step(1) with the compound containing IVB group metal and the organic solventand optionally filtering and/or drying comprises: the compoundcontaining IVB group metal, the organic solvent and the Y zeolite aremixed and contacted at a temperature in a range from room temperature to100° C. for at least 0.5 hour, then optionally filtered, and thenoptionally dried.
 13. The process of claim 9, wherein in the step (2),the procedure of contacting the dewatered Y zeolite obtained from step(1) with the mixture of the compound containing IVB group metal and theorganic solvent and optionally filtering and/or drying the resultingmixture is conducted once or more than once.
 14. The process of claim 9,wherein in the step (3), the calcination temperature is 350-650° C., thecalcination time is 2-4 hours, the calcination atmosphere is a dried airand/or an inert gas.
 15. The process of claim 9, wherein in the step(4), the condition for contacting the Y zeolite obtained from step (3)and the aqueous acid solution comprises: the weight ratio(solid-to-liquid ratio) of the Y zeolite obtained from step (3) to theaqueous acid solution is 1:5-20, the contact temperature is in a rangefrom room temperature to 100° C., the contact time is at least 0.5 hour;the aqueous acid solution has an acid concentration, as H+, of 0.1-2mol/L.
 16. The process of claim 9, wherein the aqueous acid solution hasan acid concentration, as H+, of 0.5-2 mol/L.
 17. The process of claim9, wherein the organic solvent is one or more of alkanes, aromatichydrocarbons, alcohols, ketones, ethers, esters, halogenated alkanessuch as chloridized alkanes.
 18. The process of claim 9, wherein theorganic solvent is selected from one or more of n-hexane, cyclohexane,heptane, benzene, toluene, methanol, ethanol, isopropanol, acetone,butanone, trichloromethane.
 19. The process of claim 9, wherein theorganic solvent has a normal boiling point of 40-100° C.
 20. The processof claim 9, wherein the organic solvent has a water content of not morethan 5 wt %.
 21. The process of claim 9, wherein the organic solvent hasa water content of not more than 1 wt %.
 22. The process of claim 9,wherein in the step (2), the temperature for contacting the dewatered Yzeolite obtained from step (1) and the mixture of the compoundcontaining IVB group metal and the organic solvent is such a temperaturethat allows the organic solvent in a liquid state.
 23. The process ofclaim 9, wherein the compound containing IVB group metal comprises aTi-containing compound and/or a Zr-containing compound.
 24. The processof claim 23, wherein the Ti-containing compound is one or more oftitanium sulfate, titanyl sulfate, titanium tetrachloride, titaniumtrichloride, tetrabutyl titanate, ammonium fluotitanate, and theZr-containing compound is one or more of zirconium tetrachloride,zirconium sulphate, zirconium nitrate, zirconium oxychloride, zirconiumacetate, and zirconium isopropoxide.
 25. The process of claim 9, whereinin the step (1), the Y zeolite raw material is one or more of NaYzeolite, NaHY zeolite, NaNH₄Y zeolite, NH₄Y zeolite and HY zeolite. 26.The process of claim 9, wherein in the step (1), the Y zeolite rawmaterial has a water content, after dewatering, of not more than 1 wt %.27. The process of claim 9, wherein in the step (4), the calcination isconducted in a 1-100% steam atmosphere.
 28. A metal modified Y zeolite,which contains 1-15 wt % of IVB group metal as oxide, wherein the ratioof the zeolite surface's IVB group metal content to the zeoliteinterior's IVB group metal content is not higher than 0.2, which isobtainable or obtained by the process of claim
 9. 29. A catalyticcracking catalyst, based on the total weight of the catalyst, containing10-60 wt % of a metal-modified Y zeolite, 10-60 wt % of a clay and 5-50wt % of a binder, wherein said metal-modified Y zeolite is themetal-modified Y zeolite of claim
 1. 30. The catalyst of claim 29,wherein the catalyst further contains other molecular sieves commonlyused in the catalytic cracking catalyst, said other molecular sievesinclude Y-type molecular sieves, MFI-structured molecular sieves, andSAPO molecular sieves.
 31. The catalyst of claim 29, wherein the contentof other molecular sieves commonly used in the catalytic crackingcatalyst is not more than 40 wt %, such as 1-35 wt %.
 32. A method forpreparing the catalytic cracking catalyst, which comprises the steps ofpreparing a metal-modified Y zeolite, mixing and slurrying themetal-modified Y zeolite and a clay and a binder, and spray-drying theresulting mixture, wherein said metal-modified Y zeolite is preparedaccording to the process of claim
 9. 33. The method of claim 32, whereinthe clay is selected from one or more of kaolin, halloysite, rectorite,diatomite, montmorillonite, bentonite and sepiolite; and the binder isselected from one or more of hydrated alumina, alumina sol,pseudobohemite, bohemite, alumina trihydrate, and amorphous aluminumhydroxyde.